v8.1.0 release notes

If using --tesseract-timeout 0 and any image processing on a file with
more than 100 pages, the weave handoff will occur. Ensure this
works correctly even if no Glyphless font is present.

Closes #347

.docker/Dockerfile

@@ -51,7 +51,7 @@ RUN . /appenv/bin/activate; \
 # Do this now to make the best use of Docker cache.
 COPY . /application
 RUN . /appenv/bin/activate; \
-  pip install -r /application/test_requirements.txt
+  pip install -r /application/requirements/test.txt
 
 # Remove the junk, including the source version of application since it was
 # already installed

.docker/webservice.dockerfile

@@ -0,0 +1,24 @@
+# OCRmyPDF webservice
+#
+FROM      jbarlow83/ocrmypdf-polyglot:latest
+
+USER root
+
+# Update system and install our dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  python3-flask
+
+RUN apt-get autoremove -y && apt-get clean -y
+
+EXPOSE 5000
+
+COPY .docker/webservice.py /application
+
+USER docker
+
+VOLUME ["/config"]
+
+# This config file is optional
+ENV OCRMYPDF_WEBSERVICE_SETTINGS "/config/config.py"
+
+ENTRYPOINT ["python3", "/application/webservice.py"]

.docker/webservice.py

@@ -0,0 +1,96 @@
+# webservice.py wrapper for OCRmyPDF
+# Copyright (C) 2018 James R. Barlow: github.com/jbarlow83
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+"""This is a simple web service/HTTP wrapper for OCRmyPDF
+
+This may be more convenient than the command line tool for some Docker users.
+Note that OCRmyPDF uses Ghostscript, which is licensed under AGPL3+. While
+OCRmyPDF is under GPL3, this file is distributed under the Affero GPL3+ license,
+to emphasize that SaaS deployments should make sure they comply with
+Ghostscript's license as well as OCRmyPDF's.
+"""
+
+from flask import Flask, Response, flash, request, redirect, url_for, abort, send_from_directory
+from subprocess import run, PIPE
+from tempfile import TemporaryDirectory
+from werkzeug.utils import secure_filename
+import os
+import shlex
+
+app = Flask(__name__)
+app.secret_key = "secret"
+app.config['MAX_CONTENT_LENGTH'] = 50_000_000
+app.config.from_envvar("OCRMYPDF_WEBSERVICE_SETTINGS", silent=True)
+
+ALLOWED_EXTENSIONS = set(["pdf"])
+
+
+def allowed_file(filename):
+    return "." in filename and filename.rsplit(".", 1)[1].lower() in ALLOWED_EXTENSIONS
+
+
+def do_ocrmypdf(file):
+    uploaddir = TemporaryDirectory(prefix="ocrmypdf-upload")
+    downloaddir = TemporaryDirectory(prefix="ocrmypdf-download")
+
+    filename = secure_filename(file.filename)
+    up_file = os.path.join(uploaddir.name, filename)
+    file.save(up_file)
+
+    down_file = os.path.join(downloaddir.name, filename)
+
+    cmd_args = [arg for arg in shlex.split(request.form["params"])]
+    if "--sidecar" in cmd_args:
+        return Response("--sidecar not supported", 501, mimetype='text/plain')
+
+    ocrmypdf_args = ["ocrmypdf", *cmd_args, up_file, down_file]
+    proc = run(ocrmypdf_args, stdout=PIPE, stderr=PIPE, encoding="utf-8")
+    if proc.returncode != 0:
+        stderr = proc.stderr
+        return Response(stderr, 400, mimetype='text/plain')
+
+    return send_from_directory(downloaddir.name, filename)
+
+
+@app.route("/", methods=["GET", "POST"])
+def upload_file():
+    if request.method == "POST":
+        if "file" not in request.files:
+            return Response("No file in POST", 400, mimetype='text/plain')
+        file = request.files["file"]
+        if file.filename == "":
+            return Response("Empty filename", 400, mimetype='text/plain')
+        if not allowed_file(file.filename):
+            return Response("Invalid filename", 400, mimetype='text/plain')
+        if file and allowed_file(file.filename):
+            return do_ocrmypdf(file)
+        return Response("Some other problem", 400, mimetype='text/plain')
+
+    return """
+    <!doctype html>
+    <title>OCRmyPDF webapp</title>
+    <h1>Upload a PDF (debug UI)</h1>
+    <form method=post enctype=multipart/form-data>
+      <label for="args">Command line parameters</label>
+      <input type=textbox name=params>
+      <label for="file">File to upload</label>
+      <input type=file name=file>
+      <input type=submit value=Upload>
+    </form>
+    """
+
+if __name__ == "__main__":
+    app.run(host='0.0.0.0')

.github/ISSUE_TEMPLATE

@@ -1,5 +0,0 @@
-Please include the command line and a test file with your issue report.
-
-If possible, please use a test file that we can include in future test cases (no personal information, no copyrighted material).
-
-If you wish to encrypt a test file for the OCRmyPDF maintainer only, see the [Wiki](https://github.com/jbarlow83/OCRmyPDF/wiki).

.github/issue_template.md

@@ -0,0 +1,33 @@
+**Describe the issue**
+A clear and concise description of what the issue is.
+
+**To Reproduce**
+What command line were you trying to run?
+
+```bash
+ocrmypdf  ...arguments... input.pdf output.pdf
+```
+
+**Example file**
+Please include an example *input* PDF (or image). The input file is more helpful.
+
+Please check any or all that apply about the test file:
+
+- [ ] This is the input file
+- [ ] The file contains no personal or confidential information
+- [ ] I am the copyright holder for this file
+- [ ] I permit this file to be included in the OCRmyPDF test suite under the CC-BY-SA 4.0 license
+- [ ] I am not the copyright holder, but this file is available under a free software license
+
+Files that are not free for inclusion in this project are quite welcome, but we like to collect free files for our test suite when possible. Please do *not* submit files with confidential information. At your option you may encrypt files for OCRmyPDF's author only.
+
+**Expected behavior**
+A clear and concise description of what you expected to happen. Include screenshots if applicable.
+
+**System:**
+
+- OS: [e.g. Linux, macOS]
+- OCRmyPDF Version: [e.g. v7.4.0]
+
+**Additional context**
+Add any other context about the problem here.

.gitignore

@@ -1,47 +1,43 @@
 # Development environment
+.bash_history
+.pylintrc
+.pytest_cache/
+.ruffus_history.sqlite
+.venv/
 *.pyc
 *.sublime-*
-venv*/
-.venv/
-pyvenv.cfg
-tasks.py
-.bash_history
-.ruffus_history.sqlite
-.idea/
-.pytest_cache/
-.pylintrc
 
 # Package building
-*.egg-info/
-.cache/
 .eggs/
+*.egg-info/
 build/
 dist/
 wheelhouse/
 
 # Automatically generated files
-ocrmypdf/lib/_*.py
-ocrmypdf/version.py
 docs/_build/
 docs/_static/
 docs/_templates/
 docs/Makefile
+ocrmypdf/lib/_*.py
 
 # Code coverage
-.coverage
+.coverage*
 htmlcov/
 
 # Testing
-log/
+.ipynb_checkpoints/
+.vscode/
+*.ipynb
+*.profile
 /*.pdf
 /*.qdf
-*.ipynb
-.ipynb_checkpoints/
+/*.png
+/scratch.py
+IDEAS
+log/
 tests/output/
 tests/resources/private/
 tmp/
-pdfbox-app*.jar
-.vscode/
-IDEAS
-_Dockerfile.local
-/scratch.py
+/debug_tests.py
+*.traineddata

.pre-commit-config.yaml

@@ -0,0 +1,6 @@
+repos:
+-   repo: https://github.com/ambv/black
+    rev: stable
+    hooks:
+    - id: black
+      language_version: python3.6

.readthedocs.yml

@@ -0,0 +1,10 @@
+build:
+  image: latest
+
+python:
+  version: 3.6
+
+formats:
+  - pdf
+
+requirements_file: requirements/main.txt

.travis.yml

@@ -9,7 +9,7 @@ matrix:
       dist: trusty
       sudo: required
       language: python
-      python: "3.5"
+      python: "3.6"
       env:
         - DIST=trusty
       addons: &trusty_apt
@@ -33,14 +33,6 @@ matrix:
           - tesseract-ocr-deu
           - tesseract-ocr-eng
           - tesseract-ocr-fra
-    - os: linux
-      dist: trusty
-      sudo: required
-      language: python
-      python: "3.6"
-      env:
-        - DIST=trusty
-      addons: *trusty_apt
     - os: linux
       dist: xenial
       sudo: required
@@ -66,8 +58,41 @@ matrix:
           - tesseract-ocr-fra
           - unpaper
     - os: osx
-      osx_image: xcode8
+      osx_image: xcode9.2
       language: generic
+      addons:
+        homebrew:
+          update: true
+          packages:
+            - exempi
+            - ghostscript
+            - jbig2enc
+            - leptonica
+            - openjpeg
+            - pngquant
+            - python
+            - qpdf
+            - tesseract
+            - unpaper
+    - os: osx
+      osx_image: xcode9.2
+      language: generic
+      env:
+        - ADD_PDFMINER=1
+      addons:
+        homebrew:
+          update: true
+          packages:
+            - exempi
+            - ghostscript
+            - jbig2enc
+            - leptonica
+            - openjpeg
+            - pngquant
+            - python
+            - qpdf
+            - tesseract
+            - unpaper
 
 before_cache:
 - rm -f $HOME/.cache/pip/log/debug.log
@@ -83,7 +108,6 @@ before_install: |
       sudo dpkg -i packages/unpaper_6.1-1.deb
     fi
   elif [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
-    brew update && brew bundle --file=.travis/Brewfile
     pip3 install --upgrade pip
     pip3 install wheel
   fi
@@ -91,9 +115,13 @@ before_install: |
 install:
 - export PATH=$PWD/bin:$PATH
 - pip3 install pycparser  # py3.7 workaround for https://github.com/eliben/pycparser/issues/251
-- pip3 install -r requirements.txt
+- pip3 install -r requirements/main.txt
 - pip3 install --no-deps .
-- pip3 install -r test_requirements.txt
+- |
+  if [[ "$ADD_PDFMINER" == "1" ]]; then
+    pip3 install --no-deps .[pdfminer]
+  fi
+- pip3 install -r requirements/test.txt
 
 script:
 - tesseract --version

.travis/Brewfile

@@ -1,12 +0,0 @@
-brew 'python'
-
-brew 'exempi'
-brew 'ghostscript'
-brew 'jbig2enc'
-brew 'leptonica'
-brew 'libtiff'
-brew 'openjpeg'
-brew 'pngquant'
-brew 'qpdf'
-brew 'tesseract'
-brew 'unpaper'

MANIFEST.in

@@ -1,7 +1,5 @@
 # requirements
-include requirements.txt
-include test_requirements.txt
-include dev_requirements.txt
+recursive-include requirements *
 
 # git
 include .git_archival.txt
@@ -12,21 +10,20 @@ recursive-include .docker *
 
 # tests
 include .coveragerc
+recursive-include tests *.bin
 recursive-include tests *.jpg
+recursive-include tests *.jsonl
 recursive-include tests *.png
 recursive-include tests *.pdf
 recursive-include tests *.py
 recursive-include tests *.rst
 recursive-include tests *.txt
-recursive-include tests/cache *
-recursive-exclude tests/output *
-recursive-exclude tests/output_pageinfo *
 recursive-exclude tests/resources/private *
 
 # documentation
 include LICENSE
 include *.rst
-recursive-exclude .github * 
+recursive-exclude .github *
 recursive-include docs *.py
 recursive-include docs *.rst
 recursive-include docs *.svg
@@ -42,8 +39,5 @@ exclude .travis*
 
 
 # code
-recursive-include src/ocrmypdf *.py
-exclude ocrmypdf/lib/_leptonica.py
-
-
-
+exclude src/ocrmypdf/lib/_leptonica.py
+exclude scratch.py

README.md

@@ -0,0 +1,146 @@
+OCRmyPDF
+========
+
+[![Travis build status][travis]](https://travis-ci.org/jbarlow83/OCRmyPDF) [![PyPI version][pypi]](https://pypi.org/project/ocrmypdf/) ![Homebrew version][homebrew] ![ReadTheDocs][docs]
+
+[travis]: https://travis-ci.org/jbarlow83/OCRmyPDF.svg?branch=master "Travis build status"
+
+[pypi]: https://img.shields.io/pypi/v/ocrmypdf.svg "PyPI version"
+
+[homebrew]: https://img.shields.io/homebrew/v/ocrmypdf.svg "Homebrew version"
+
+[docs]: https://readthedocs.org/projects/ocrmypdf/badge/?version=latest "RTD"
+
+OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to be searched or copy-pasted.
+
+```bash
+ocrmypdf                      # it's a scriptable command line program
+   -l eng+fra                 # it supports multiple languages
+   --rotate-pages             # it can fix pages that are misrotated
+   --deskew                   # it can deskew crooked PDFs!
+   --title "My PDF"           # it can change output metadata
+   --jobs 4                   # it uses multiple cores by default
+   --output-type pdfa         # it produces PDF/A by default
+   input_scanned.pdf          # takes PDF input (or images)
+   output_searchable.pdf      # produces validated PDF output
+```
+
+[See the release notes for details on the latest changes](https://ocrmypdf.readthedocs.io/en/latest/release_notes.html).
+
+Main features
+-------------
+
+- Generates a searchable [PDF/A](https://en.wikipedia.org/?title=PDF/A) file from a regular PDF
+- Places OCR text accurately below the image to ease copy / paste
+- Keeps the exact resolution of the original embedded images
+- When possible, inserts OCR information as a "lossless" operation without disrupting any other content
+- Optimizes PDF images, often producing files smaller than the input file
+- If requested deskews and/or cleans the image before performing OCR
+- Validates input and output files
+- Distributes work across all available CPU cores
+- Uses [Tesseract OCR](https://github.com/tesseract-ocr/tesseract) engine
+- Supports more than [100 languages](https://github.com/tesseract-ocr/tessdata) recognized by Tesseract
+- Battle-tested on thousands of PDFs, a test suite and continuous integration
+
+For details: please consult the [documentation](https://ocrmypdf.readthedocs.io/en/latest/).
+
+Motivation
+----------
+
+I searched the web for a free command line tool to OCR PDF files on Linux/UNIX: I found many, but none of them were really satisfying.
+
+- Either they produced PDF files with misplaced text under the image (making copy/paste impossible)
+- Or they did not handle accents and multilingual characters
+- Or they changed the resolution of the embedded images
+- Or they generated ridiculously large PDF files
+- Or they crashed when trying to OCR
+- Or they did not produce valid PDF files
+- On top of that none of them produced PDF/A files (format dedicated for long time storage)
+
+...so I decided to develop my own tool.
+
+Installation
+------------
+
+Linux, UNIX, and macOS are supported. Windows is not directly supported but there is a Docker image available that runs on Windows.
+
+Users of Debian 9 or later or Ubuntu 16.10 or later may simply
+
+```bash
+apt-get install ocrmypdf
+```
+
+and users of Fedora 29 or later may simply
+
+```bash
+dnf install ocrmypdf
+```
+
+and macOS users with Homebrew may simply
+
+```bash
+brew install ocrmypdf
+```
+
+For everyone else, [see our documentation](https://ocrmypdf.readthedocs.io/en/latest/installation.html) for installation steps.
+
+Languages
+---------
+
+OCRmyPDF uses Tesseract for OCR, and relies on its language packs. For Linux users, you can often find packages that provide language packs:
+
+```bash
+# Display a list of all Tesseract language packs
+apt-cache search tesseract-ocr
+
+# Debian/Ubuntu users
+apt-get install tesseract-ocr-chi-sim  # Example: Install Chinese Simplified language back
+```
+
+You can then pass the `-l LANG` argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple languages can be requested.
+
+Documentation and support
+-------------------------
+
+Once ocrmypdf is installed, the built-in help which explains the command syntax and options can be accessed via:
+
+```bash
+ocrmypdf --help
+```
+
+Our [documentation is served on Read the Docs](https://ocrmypdf.readthedocs.io/en/latest/index.html).
+
+If you detect an issue, please:
+
+- Check whether your issue is already known
+- If no problem report exists on github, please create one here: <https://github.com/jbarlow83/OCRmyPDF/issues>
+- Describe your problem thoroughly
+- Append the console output of the script when running the debug mode (`-v 1` option)
+- If possible provide your input PDF file as well as the content of the temporary folder (using a file sharing service like Dropbox)
+
+Requirements
+------------
+
+Runs on CPython 3.5, 3.6 and 3.7. Requires external program installations of Ghostscript, Tesseract OCR, QPDF, and Leptonica. ocrmypdf is pure Python, but uses CFFI to portably generate library bindings.
+
+Press & Media
+-------------
+
+- [Going paperless with OCRmyPDF](https://medium.com/@ikirichenko/going-paperless-with-ocrmypdf-e2f36143f46a)
+- [Converting a scanned document into a compressed searchable PDF with redactions](https://medium.com/@treyharris/converting-a-scanned-document-into-a-compressed-searchable-pdf-with-redactions-63f61c34fe4c)
+- [c't 1-2014, page 59](http://heise.de/-2279695): Detailed presentation of OCRmyPDF v1.0 in the leading German IT magazine c't
+- [heise Open Source, 09/2014: Texterkennung mit OCRmyPDF](http://heise.de/-2356670)
+
+License
+-------
+
+The OCRmyPDF software is licensed under the GNU GPLv3. Certain files are covered by other licenses, as noted in their source files.
+
+The license for each test file varies, and is noted in tests/resources/README.rst. The documentation is licensed under Creative Commons Attribution-ShareAlike 4.0 (CC-BY-SA 4.0).
+
+OCRmyPDF versions prior to 6.0 were licensed under the MIT License.
+
+Disclaimer
+----------
+
+The software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

README.rst

@@ -1,150 +0,0 @@
-OCRmyPDF
-========
-
-.. image:: https://travis-ci.org/jbarlow83/OCRmyPDF.svg?branch=master
-    :target: https://travis-ci.org/jbarlow83/OCRmyPDF
-
-.. image:: https://img.shields.io/pypi/v/ocrmypdf.svg
-    :target: https://pypi.org/project/ocrmypdf/
-
-.. image:: https://img.shields.io/homebrew/v/ocrmypdf.svg
-    :alt: homebrew
-    :target: http://brewformulas.org/Ocrmypdf
-
-
-OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to
-be searched or copy-pasted.
-
-.. code-block:: bash
-
-   ocrmypdf                      # it's a scriptable command line program
-      -l eng+fra                 # it supports multiple languages
-      --rotate-pages             # it can fix pages that are misrotated
-      --deskew                   # it can deskew crooked PDFs!
-      --title "My PDF"           # it can change output metadata
-      --jobs 4                   # it uses multiple cores by default
-      --output-type pdfa         # it produces PDF/A by default
-      input_scanned.pdf          # takes PDF input (or images)
-      output_searchable.pdf      # produces validated PDF output
-
-
-Main features
--------------
-
--  Generates a searchable
-   `PDF/A <https://en.wikipedia.org/?title=PDF/A>`_ file from a regular PDF
--  Places OCR text accurately below the image to ease copy / paste
--  Keeps the exact resolution of the original embedded images
--  When possible, inserts OCR information as a "lossless" operation without disrupting any other content
--  Optimizes PDF images, often producing files smaller than the input file
--  If requested deskews and/or cleans the image before performing OCR
--  Validates input and output files
--  Distributes work across all available CPU cores
--  Uses `Tesseract OCR <https://github.com/tesseract-ocr/tesseract>`_ engine
--  Supports more than `100 languages <https://github.com/tesseract-ocr/tessdata>`_ recognized by Tesseract
--  Battle-tested on thousands of PDFs, a test suite and continuous integration
-
-For details: please consult the `documentation <https://ocrmypdf.readthedocs.io/en/latest/>`_.
-
-Motivation
-----------
-
-I searched the web for a free command line tool to OCR PDF files on
-Linux/UNIX: I found many, but none of them were really satisfying.
-
--  Either they produced PDF files with misplaced text under the image (making copy/paste impossible)
--  Or they did not handle accents and multilingual characters
--  Or they changed the resolution of the embedded images
--  Or they generated ridiculously large PDF files
--  Or they crashed when trying to OCR
--  Or they did not produce valid PDF files
--  On top of that none of them produced PDF/A files (format dedicated for long time storage)
-
-...so I decided to develop my own tool.
-
-Installation
-------------
-
-Linux, UNIX, and macOS are supported. Windows is not directly supported but there is a Docker image available that runs on Windows.
-
-Users of Debian 9 or later or Ubuntu 16.10 or later may simply
-
-.. code-block:: bash
-
-   apt-get install ocrmypdf
-
-and macOS users with Homebrew may simply
-
-.. code-block:: bash
-
-   brew install ocrmypdf
-
-For everyone else, `see our documentation <https://ocrmypdf.readthedocs.io/en/latest/installation.html>`_ for installation steps.
-
-Languages
----------
-
-OCRmyPDF uses Tesseract for OCR, and relies on its language packs. For Linux users,
-you can often find packages that provide language packs:
-
-.. code-block:: bash
-
-   # Display a list of all Tesseract language packs
-   apt-cache search tesseract-ocr
-
-   # Debian/Ubuntu users
-   apt-get install tesseract-ocr-chi-sim  # Example: Install Chinese Simplified language back
-
-You can then pass the ``-l LANG`` argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple
-languages can be requested.
-
-Documentation and support
--------------------------
-
-Once ocrmypdf is installed, the built-in help which explains the command syntax and options can be accessed via:
-
-.. code-block:: bash
-
-   ocrmypdf --help
-
-Our `documentation is served on Read the Docs <https://ocrmypdf.readthedocs.io/en/latest/index.html>`_.
-
-If you detect an issue, please:
-
--  Check whether your issue is already known
--  If no problem report exists on github, please create one here:
-   https://github.com/jbarlow83/OCRmyPDF/issues
--  Describe your problem thoroughly
--  Append the console output of the script when running the debug mode
-   (``-v 1`` option)
--  If possible provide your input PDF file as well as the content of the
-   temporary folder (using a file sharing service like Dropbox)
-
-Requirements
-------------
-
-Runs on CPython 3.5, 3.6 and 3.7. Requires external program installations of Ghostscript, Tesseract OCR, QPDF, and Leptonica. ocrmypdf is pure Python, but uses CFFI to portably generate library bindings.
-
-Press & Media
--------------
-
--  `c't 1-2014, page 59 <http://heise.de/-2279695>`_:
-   Detailed presentation of OCRmyPDF v1.0 in the leading German IT
-   magazine c't
--  `heise Open Source, 09/2014: Texterkennung mit
-   OCRmyPDF <http://heise.de/-2356670>`_
-
-License
--------
-
-The OCRmyPDF software is licensed under the GNU GPLv3. Certain files are covered by other licenses, as noted in their source files.
-
-The license for each test file varies, and is noted in tests/resources/README.rst. The documentation is licensed under Creative Commons Attribution-ShareAlike 4.0 (CC-BY-SA 4.0).
-
-OCRmyPDF versions prior to 6.0 were licensed under the MIT License.
-
-Disclaimer
-----------
-
-The software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
-CONDITIONS OF ANY KIND, either express or implied.

docs/advanced.rst

@@ -1,6 +1,34 @@
 Advanced features
 =================
 
+Control of unpaper
+------------------
+
+OCRmyPDF uses ``unpaper`` to provide the implementation of the ``--clean`` and ``--clean-final`` arguments. `unpaper <https://github.com/Flameeyes/unpaper/blob/master/doc/basic-concepts.md>`_ provides a variety of image processing filters to improve images.
+
+By default, OCRmyPDF uses only ``unpaper`` arguments that were found to be safe to use on almost all files without having to inspect every page of the file afterwards. This is particularly true when only ``--clean`` is used, since that instructs OCRmyPDF to only clean the image before OCR and not the final image.
+
+However, if you wish to use the more aggressive options in ``unpaper``, you may use ``--unpaper-args '...'`` to override the OCRmyPDF's defaults and forward other arguments to unpaper. This option will forward arguments to ``unpaper`` without any knowledge of what that program considers to be valid arguments. The string of arguments must be quoted as shown in the examples below. No filename arguments may be included. OCRmyPDF will assume it can append input and output filename of intermediate images to the ``--unpaper-args`` string.
+
+In this example, we tell ``unpaper`` to expect two pages of text on a sheet (image), such as occurs when two facing pages of a book are scanned. ``unpaper`` uses this information to deskew each independently and clean up the margins of both.
+
+.. code-block:: bash
+
+    ocrmypdf --clean --clean-final --unpaper-args '--layout double' input.pdf output.pdf
+    ocrmypdf --clean --clean-final --unpaper-args '--layout double --no-noisefilter' input.pdf output.pdf
+
+.. warning::
+
+    Some ``unpaper`` features will reposition text within the image. ``--clean-final`` is recommended to avoid this issue.
+
+.. warning::
+
+    Some ``unpaper`` features cause multiple input or output files to be consumed or produced. OCRmyPDF requires ``unpaper`` to consume one file and produce one file. An deviation from that condition will result in errors.
+
+.. note::
+
+    ``unpaper`` uses uncompressed PBM/PGM/PPM files for its intermediate files. For large images or documents, it can take a lot of temporary disk space.
+
 Control of OCR options
 ----------------------
 
@@ -13,8 +41,9 @@ If a page in a PDF seems to have text, by default OCRmyPDF will exit without mod
 
 If ``--skip-text`` is issued, then no OCR will be performed on pages that already have text. The page will be copied to the output. This may be useful for documents that contain both "born digital" and scanned content, or to use OCRmyPDF to normalize and convert to PDF/A regardless of their contents.
 
-If ``--force-ocr`` is issued, then all pages will be rasterized to images, discarding any hidden OCR text, and rasterizing any printable text. This is useful for redoing OCR, for fixing OCR text with a damaged character map (text is selectable but not searchable), and destroying redacted information.
+If ``--redo-ocr`` is issued, then a detailed text analysis is performed. Text is categorized as either visible or invisible. Invisible text (OCR) is stripped out. Then an image of each page is created with visible text masked out. The page image is sent for OCR, and any additional text is inserted as OCR. If a file contains a mix of text and bitmap images that contain text, OCRmyPDF will locate the additional text in images without disrupting the existing text.
 
+If ``--force-ocr`` is issued, then all pages will be rasterized to images, discarding any hidden OCR text, and rasterizing any printable text. This is useful for redoing OCR, for fixing OCR text with a damaged character map (text is selectable but not searchable), and destroying redacted information. Any forms and vector graphics will be rasterized as well.
 
 Time and image size limits
 """"""""""""""""""""""""""
@@ -45,16 +74,16 @@ Some relevant environment variables that influence Tesseract's behavior include:
 
     Controls the number of threads Tesseract will use. OCRmyPDF will manage this environment if it is not already set. (Currently, it will set it to 1 because this gives the best results in testing.)
 
-For example, if you are testing tesseract 4.00 and don't wish to use an existing tesseract 3.04 installation, you can launch OCRmyPDF as follows:
+For example, if you have a development build of Tesseract don't wish to use the system installation, you can launch OCRmyPDF as follows:
 
 .. code-block:: bash
 
     env \
-        PATH=/home/user/src/tesseract4/api:$PATH \
-        TESSDATA_PREFIX=/home/user/src/tesseract4 \
-        ocrmypdf --tesseract-oem 2 input.pdf output.pdf
+        PATH=/home/user/src/tesseract/api:$PATH \
+        TESSDATA_PREFIX=/home/user/src/tesseract \
+        ocrmypdf input.pdf output.pdf
 
-In this example ``TESSDATA_PREFIX`` directs Tesseract 4.0 to use LSTM training data. ``--tesseract-oem 1`` requests tesseract 4.0's new LSTM engine. (Tesseract 4.0 only.)
+In this example ``TESSDATA_PREFIX`` is required to redirect Tesseract to an alternate folder for its "tessdata" files.
 
 
 Overriding other support programs
@@ -105,7 +134,7 @@ rendering
   Creating a new PDF from other data (such as an existing PDF).
 
 
-OCRmyPDF has these PDF renderers: ``sandwich`` and ``hocr``. The renderer may be selected using ``--pdf-renderer``. The default is ``auto`` which lets OCRmyPDF select the renderer to use. Currently, ``auto`` selects ``sandwich`` for Tesseract 3.05.01 or newer, or ``hocr`` for older versions of Tesseract.
+OCRmyPDF has these PDF renderers: ``sandwich`` and ``hocr``. The renderer may be selected using ``--pdf-renderer``. The default is ``auto`` which lets OCRmyPDF select the renderer to use. Currently, ``auto`` always selects ``sandwich``.
 
 The ``sandwich`` renderer
 """""""""""""""""""""""""
@@ -116,8 +145,6 @@ Currently this is the best renderer for most uses, however it is implemented in
 
 When image preprocessing features like ``--deskew`` are used, the original PDF will be rendered as a full page and the OCR layer will be placed on top.
 
-If a PDF created with this renderer using Tesseract versions older than 3.05.00 is then passed through Ghostscript's pdfwrite feature, the OCR text *may* be corrupted. The ``--output-type=pdfa`` argument will produce a warning in this situation.  For this reason, OCRmyPDF automatically selects the ``hocr`` for older Tesseract versions.
-
 The ``hocr`` renderer
 """""""""""""""""""""
 
@@ -189,3 +216,25 @@ user interface.  They may be imported from ``ocrmypdf.exceptions``.
     *	- 130
         - ``ExitCode.ctrl_c``
         - The program was interrupted by pressing Ctrl+C.
+
+
+Debugging the intermediate files
+--------------------------------
+
+OCRmyPDF normally saves its intermediate results to a temporary folder and deletes this folder when it exits, whether it succeeded or failed.
+
+If the ``-k`` argument is issued on the command line, OCRmyPDF will keep the temporary folder and print the location, whether it succeeded or failed (provided the Python interpreter did not crash). An example message is:
+
+.. code-block::
+
+    Temporary working files saved at:
+    /tmp/com.github.ocrmypdf.u20wpz07
+
+The organization of this folder is an implementation detail and subject to change between releases. However the general organization is that working files on a per page basis have the page number as a prefix (starting with page 1), an infix indicates the processing stage, and a suffix indicates the file type. Some important files include:
+
+* ``.page.png`` - what the input page looks like
+* ``.image`` - the image we will show the user if we are in a mode that changes the final appearance; may be in one of several image formats
+* ``.text.pdf`` - the OCR file; this will load as a blank page but should have visible text if checked with a tool like pdftotext or pdfminder.six
+* ``.ocr.png`` - the file that is sent to Tesseract for OCR; depending on arguments this may differ from the presentation image
+* ``layers.rendered.pdf`` - the composite PDF, before metadata repair and optimization
+* ``images/*`` - images extracted during the optimization process; here the prefix indicates a PDF object ID not a page number

docs/batch.rst

@@ -18,12 +18,12 @@ The ``--tag`` argument tells parallel to print the filename as a prefix whenever
 
 	parallel --tag -j 2 ocrmypdf '{}' 'output/{}' ::: *.pdf
 
-OCRmyPDF automatically repairs PDFs before parsing and gathering information from them.  If you are already repairing PDFs with ``qpdf`` prior to attempting OCR, or you can use ``--skip-repair`` to skip this step.  It may improve performance for large files, since repairing PDFs is single-threaded.
+OCRmyPDF automatically repairs PDFs before parsing and gathering information from them.
 
 Directory trees
 ---------------
 
-This will walk through a directory tree and run OCR on all files in place, printing the output in a way that makes 
+This will walk through a directory tree and run OCR on all files in place, printing the output in a way that makes
 
 .. code-block:: bash
 
@@ -66,7 +66,7 @@ This user contributed script also provides an example of batch processing.
 	    log_file = script_dir + '/ocr-tree.log'
 
 	logging.basicConfig(
-			level=logging.INFO, format='%(asctime)s %(message)s', 
+			level=logging.INFO, format='%(asctime)s %(message)s',
 			filename=log_file, filemode='w')
 
 	for dir_name, subdirs, file_list in os.walk(start_dir):
@@ -144,11 +144,11 @@ This is only possible for x86-based Synology products. Some Synology products us
 	            timestamp_OCR = time.strftime("%Y-%m-%d-%H%M_OCR_")
 	            filename_OCR = timestamp_OCR + file_noext + '.pdf'
 	            docker_mount = dir_name + ':/home/docker'
-	# create string for pdf processing 
+	# create string for pdf processing
 	# diskstation needs a user:group docker:docker. find uid:gid of your diskstation docker:docker with id docker.
 	# use this uid:gid in -u flag
 	# rw rights for docker:docker at source dir are also necessary
-	# the script is processed as root user via chron 
+	# the script is processed as root user via chron
 	            cmd = ['docker', 'run', '--rm', '-v', docker_mount, '-u=1030:65538', 'jbarlow83/ocrmypdf', , '--deskew' , filename, filename_OCR]
 	            logging.info(cmd)
 	            proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
@@ -210,5 +210,3 @@ Alternatives
 """"""""""""
 
 * `Watchman <https://facebook.github.io/watchman/>`_ is a more powerful alternative to ``watchmedo``.
-
-

docs/conf.py

@@ -74,7 +74,12 @@ if on_rtd:
         def __getattr__(cls, name):
             return MagicMock()
 
-    MOCK_MODULES = ['pikepdf', 'libxmp', 'libxmp.utils']
+    MOCK_MODULES = [
+        'pikepdf',
+        'pikepdf.models',
+        'pikepdf.models.metadata',
+        'ocrmypdf.leptonica'
+    ]
     sys.modules.update((mod_name, Mock()) for mod_name in MOCK_MODULES)
 
 

docs/cookbook.rst

@@ -57,7 +57,6 @@ You can increase (decrease) the parameter ``--rotate-pages-threshold`` to make p
 
 If the page is "just a little off horizontal", like a crooked picture, then you want ``--deskew``. ``--rotate-pages`` is for when the cardinal angle is wrong.
 
-
 OCR languages other than English
 """"""""""""""""""""""""""""""""
 
@@ -70,7 +69,6 @@ By default OCRmyPDF assumes the document is English.
 
 Language packs must be installed for all languages specified. See :ref:`Installing additional language packs <lang-packs>`.
 
-
 Produce PDF and text file containing OCR text
 """""""""""""""""""""""""""""""""""""""""""""
 
@@ -83,7 +81,7 @@ This produces a file named "output.pdf" and a companion text file named "output.
 OCR images, not PDFs
 --------------------
 
-If you are starting with images, you can just use Tesseract 3.04 or later directly to convert images to PDFs:
+If you are starting with images, you can just use Tesseract directly to convert images to PDFs:
 
 .. code-block:: bash
 
@@ -94,7 +92,7 @@ If you are starting with images, you can just use Tesseract 3.04 or later direct
     # When there are multiple images
     tesseract text-file-containing-list-of-image-filenames.txt output-prefix pdf
 
-Tesseract's PDF output is quite good – OCRmyPDF uses it by internally by default. However, OCRmyPDF has many features not available in Tesseract like like image processing, metadata control, and PDF/A generation.
+Tesseract's PDF output is quite good – OCRmyPDF uses it internally by default. However, OCRmyPDF has many features not available in Tesseract like like image processing, metadata control, and PDF/A generation.
 
 Use a program like `img2pdf <https://gitlab.mister-muffin.de/josch/img2pdf>`_ to convert your images to PDFs, and then pipe the results to run ocrmypdf.  The `-` tells ocrmypdf to read standard input.
 
@@ -116,7 +114,6 @@ If you have multiple images, you must use ``img2pdf`` to convert the images to P
 
     ImageMagick ``convert`` can also convert a group of images to PDF, but in the author's experience it takes a long time, transcodes unnecessarily and gives poor results.
 
-
 Image processing
 ----------------
 
@@ -132,6 +129,8 @@ OCRmyPDF perform some image processing on each page of a PDF, if desired.  The s
 
 * ``--clean-final`` uses unpaper to clean up pages before OCR and inserts the page into the final output.  You will want to review each page to ensure that unpaper did not remove something important.
 
+* ``--mask-barcodes`` will "cover up" any barcodes detected in the image of a page. Barcodes are known to confuse Tesseract OCR and interfere with the recognition of text on the same baseline as a barcode. The output file will contain the unaltered image of the barcode.
+
 .. note::
 
     In many cases image processing will rasterize PDF pages as images, potentially losing quality.
@@ -140,7 +139,6 @@ OCRmyPDF perform some image processing on each page of a PDF, if desired.  The s
 
     ``--clean-final`` and ``-remove-background`` may leave undesirable visual artifacts in some images where their algorithms have shortcomings. Files should be visually reviewed after using these options.
 
-
 OCR and correct document skew (crooked scan)
 """"""""""""""""""""""""""""""""""""""""""""
 
@@ -167,28 +165,22 @@ If you set ``--tesseract-timeout 0`` OCRmyPDF will apply its image processing wi
     ocrmypdf --tesseract-timeout=0 --remove-background input.pdf output.pdf
 
 
-Redo OCR
-""""""""
+Redo existing OCR
+"""""""""""""""""
 
-To redo OCR on a file OCRed with other OCR software or a previous version of OCRmyPDF and/or Tesseract, you may use the ``--force-ocr`` argument. Normally, OCRmyPDF does not modify files that already appear to contain OCR text.
+To redo OCR on a file OCRed with other OCR software or a previous version of OCRmyPDF and/or Tesseract, you may use the ``--redo-ocr`` argument. (Normally, OCRmyPDF will exit with an error if asked to modify a file with OCR.)
+
+This may be helpful for users who want to take advantage of accuracy improvements in Tesseract 4.0 for files they previously OCRed with an earlier version of Tesseract and OCRmyPDF.
 
 .. code-block:: bash
 
-    ocrmypdf --force-ocr input.pdf output.pdf
+    ocrmypdf --redo-ocr input.pdf output.pdf
 
-Note that the method above will force rasterization of all pages, potentially reducing quality or losing vector content.
+This method will replace OCR without rasterizing, reducing quality or removing vector content. If a file contains a mix of pure digital text and OCR, digital text will be ignored and OCR will be replaced. As such this mode is incompatible with image processing options, since they alter the appearance of the file.
 
-To ensure quality is preserved, one could extract all of the images and rebuild the PDF for a lossless transformation. This recipe does not work when PDFs contain multiple images per page, as many do in practice. It will also lose any page rotation information.
-
-.. code-block:: bash
-
-    pdfimages -all old-ocr.pdf prefix  # extract all images
-    img2pdf -o temp.pdf prefix*        # construct new PDF from the images
-    # review the new PDF to ensure it visually matches the old one
-    ocrmypdf --output-type pdf temp.pdf new-ocr.pdf
-
-``--output-type pdf`` is used here to avoid using Ghostscript which will also rasterize images.
+In some cases, existing OCR cannot be detected or replaced. Files produced by OCRmyPDF v2.2 or earlier, for example, are internally represented as having visible text with an opaque image drawn on top. This situation cannot be detected.
 
+If ``--redo-ocr`` does not work, you can use ``--force-ocr``, which will force rasterization of all pages, potentially reducing quality or losing vector content.
 
 Improving OCR quality
 ---------------------
@@ -199,7 +191,6 @@ Rotating pages and deskewing helps to ensure that the page orientation is correc
 
 OCR quality will suffer if the resolution of input images is not correct (since the range of pixel sizes that will be checked for possible fonts will also be incorrect).
 
-
 PDF optimization
 ----------------
 
@@ -213,4 +204,6 @@ Currently optimization attempts to find more efficient encodings for images. The
 
 .. code-block:: bash
 
-    ocrmypdf --optimize 3 in.pdf out.pdf  # Make it as small as possible
+    ocrmypdf --optimize 3 in.pdf out.pdf  # Make it small
+
+Some users may consider enabling lossy JBIG2. See: :ref:`jbig2-lossy`.

docs/installation.rst

@@ -6,9 +6,12 @@ Installation
 
 |latest|
 
-The easiest way to install OCRmyPDF to follow the steps for your operating system/platform.
+The easiest way to install OCRmyPDF is to follow the steps for your operating
+system/platform, although sometimes this version may be out of date.
 
-If you want to use the latest version of OCRmyPDF, your best bet is to install the most recent version your platform provides, and then upgrade that version by installing the Python binary wheels.
+If you want to use the latest version of OCRmyPDF, your best bet is to install
+the most recent version your platform provides, and then upgrade that version by
+installing the Python binary wheels.
 
 .. contents:: Platform-specific steps
     :depth: 2
@@ -40,7 +43,7 @@ Debian and Ubuntu 16.10 or newer
 
 
 +-------------------------------------------+
-| **OCRmyPDF version**                      |
+| **OCRmyPDF versions in Debian & Ubuntu**  |
 +-------------------------------------------+
 | |latest|                                  |
 +-------------------------------------------+
@@ -55,13 +58,52 @@ Users of Debian 9 ("stretch") or later or Ubuntu 16.10 or later may simply
 
     apt-get install ocrmypdf
 
-For full details on version availability, check the `Debian Package Tracker <https://tracker.debian.org/pkg/ocrmypdf>`_ or `Ubuntu launchpad.net <https://launchpad.net/ocrmypdf>`_.
+As indicated in the table above, Debian and Ubuntu releases may lag behind the latest version. If the version available for your platform is out of date, you could opt to install the latest version from source. See `Installing HEAD revision from sources`_.
 
-If the version available for your platform is out of date, you could opt to install the latest version from source. See `Installing HEAD revision from sources`_.
+For full details on version availability for your platform, check the `Debian Package Tracker <https://tracker.debian.org/pkg/ocrmypdf>`_ or `Ubuntu launchpad.net <https://launchpad.net/ocrmypdf>`_.
 
 .. note::
 
-    OCRmyPDF for Debian and Ubuntu currently omit the JBIG2 encoder. OCRmyPDF works fine without it but will produce larger output files. If you build jbig2enc from source, ocrmypdf 7.0.0 and later will automatically detect it on the ``PATH``. To add JBIG2 encoding, see `Installing the JBIG2 encoder`_.
+    OCRmyPDF for Debian and Ubuntu currently omit the JBIG2 encoder. OCRmyPDF works fine without it but will produce larger output files. If you build jbig2enc from source, ocrmypdf 7.0.0 and later will automatically detect it (specifically the ``jbig2`` binary) on the ``PATH``. To add JBIG2 encoding, see :ref:`jbig2`.
+
+Fedora 29 or newer
+^^^^^^^^^^^^^^^^^^
+
+.. |fedora-29| image:: https://repology.org/badge/version-for-repo/fedora29/ocrmypdf.svg
+    :alt: Fedora 29
+
+.. |fedora-rawhide| image:: https://repology.org/badge/version-for-repo/fedora_rawhide/ocrmypdf.svg
+    :alt: Fedore Rawhide
+
+
++------------------------------+
+| **OCRmyPDF version**         |
++------------------------------+
+| |latest|                     |
++------------------------------+
+| |fedora-29| |fedora-rawhide| |
++------------------------------+
+
+Users of Fedora 29 later may simply
+
+.. code-block:: bash
+
+    dnf install ocrmypdf
+
+For full details on version availability, check the `Fedora Package Tracker
+<https://apps.fedoraproject.org/packages/ocrmypdf>`_.
+
+If the version available for your platform is out of date, you could opt to
+install the latest version from source. See `Installing HEAD revision from
+sources`_.
+
+.. note::
+
+    OCRmyPDF for Fedora currently omits the JBIG2 encoder due to patent issues.
+    OCRmyPDF works fine without it but will produce larger output files. If you
+    build jbig2enc from source, ocrmypdf 7.0.0 and later will automatically
+    detect it on the ``PATH``. To add JBIG2 encoding, see `Installing the JBIG2
+    encoder`_.
 
 Installing the latest version on Ubuntu 18.04 LTS
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -92,27 +134,61 @@ Then install the most recent ocrmypdf for the local user and set the user's ``PA
     export PATH=$HOME/.local/bin:$PATH
     pip3 install --user ocrmypdf
 
-To add JBIG2 encoding, see `Installing the JBIG2 encoder`_.
+To add JBIG2 encoding, see :ref:`jbig2`.
 
 Ubuntu 16.04 LTS
 ^^^^^^^^^^^^^^^^
 
-No package is currently available for Ubuntu 16.04, but you can install the dependencies manually:
+No package is available for Ubuntu 16.04. OCRmyPDF 8.0 and newer require Python
+3.6. Ubuntu 16.04 ships Python 3.5, but you can install Python 3.6 on it. Or,
+you can skip Python 3.6 and install OCRmyPDF 7.x or older - for that procedure,
+please see the installation documentation for the version of OCRmyPDF you plan
+to use.
+
+**Install system packages for OCRmyPDF**
 
 .. code-block:: bash
 
     sudo apt-get update
-    sudo apt-get install \
+    sudo apt-get install -y software-properties-common python-software-properties
+    sudo add-apt-repository -y \
+        ppa:jonathonf/python-3.6 \
+        ppa:alex-p/tesseract-ocr
+    sudo apt-get update
+    sudo apt-get install -y \
         ghostscript \
         libexempi3 \
+        libffi6 \
         pngquant \
-        python3-cffi \
-        python3-pip \
+        python3.6 \
         qpdf \
         tesseract-ocr \
         unpaper
 
-If you wish install OCRmyPDF for the current user, and ensure that the ``PATH``
+This will install a Python 3.6 binary at ``/usr/bin/python3.6`` alongside the
+system's Python 3.5. Do not remove the system Python. This will also install
+Tesseract 4.0 from a PPA, since the version available in Ubuntu 16.04 is too old
+for OCRmyPDF.
+
+Now install pip for Python 3.6. This will install the Python 3.6 version of
+``pip`` at ``/usr/local/bin/pip``.
+
+.. code-block:: bash
+
+    curl https://bootstrap.pypa.io/get-pip.py | sudo python3.6
+
+**Install OCRmyPDF**
+
+OCRmyPDF requires the locale to be set for UTF-8. **On some minimal Ubuntu
+installations systems**, it may be necessary to set the locale.
+
+.. code-block:: bash
+
+    # Optional: Only need to set these if they are not already set
+    export LC_ALL=C.UTF-8
+    export LANG=C.UTF-8
+
+Now install OCRmyPDF for the current user, and ensure that the ``PATH``
 environment variable contains ``$HOME/.local/bin``.
 
 .. code-block:: bash
@@ -120,38 +196,20 @@ environment variable contains ``$HOME/.local/bin``.
     export PATH=$HOME/.local/bin:$PATH
     pip3 install --user ocrmypdf
 
-Alternately, you can install ocrmypdf system-wide. (Not recommended.)
-
-.. code-block:: bash
-
-    sudo pip3 install ocrmypdf
-
-At your option, you may upgrade Ubuntu 16.04 LTS to Tesseract 4.0 for improved OCR results.
-
-.. code-block:: bash
-
-    sudo apt-get install -y software-properties-common python-software-properties
-    sudo add-apt-repository ppa:alex-p/tesseract-ocr -y
-    sudo apt-get update
-    sudo apt-get upgrade tesseract-ocr
-
-To add JBIG2 encoding, see `Installing the JBIG2 encoder`_.
+To add JBIG2 encoding, see :ref:`jbig2`.
 
 Ubuntu 14.04 LTS
 ^^^^^^^^^^^^^^^^
 
-Installing on Ubuntu 14.04 LTS (trusty) is more difficult than some other options, because it is older and does not provide ``pip``.
-
-Update apt-get:
-
-.. code-block:: bash
-
-    sudo apt-get update
+Installing on Ubuntu 14.04 LTS (trusty) is more difficult than some other
+options, because of its age. Several backports are required. For explanations of
+some steps of this procedure, see the similar steps for Ubuntu 16.04.
 
 Install system dependencies:
 
 .. code-block:: bash
 
+    sudo apt-get update
     sudo apt-get install \
         software-properties-common python-software-properties \
         zlib1g-dev \
@@ -161,9 +219,13 @@ Install system dependencies:
         pngquant \
         qpdf
 
-We will need backports of Ghostscript 9.16, libav-11 (for unpaper 6.1), Tesseract 4.00 (alpha), and Python 3.6. This will replace Ghostscript and Tesseract 3.x on your system. Python 3.6 will be installed alongside the system Python 3.4.
+We will need backports of Ghostscript 9.16, libav-11 (for unpaper 6.1),
+Tesseract 4.00 (alpha), and Python 3.6. This will replace Ghostscript and
+Tesseract 3.x on your system. Python 3.6 will be installed alongside the system
+Python 3.4.
 
-If you prefer to not modify your system in this matter, consider using a Docker container.
+If you prefer to not modify your system in this matter, consider using a Docker
+container.
 
 .. code-block:: bash
 
@@ -189,8 +251,6 @@ Now we need to install ``pip`` and let it install ocrmypdf:
     curl https://bootstrap.pypa.io/ez_setup.py -o - | python3.6 && python3.6 -m easy_install pip
     pip3.6 install ocrmypdf
 
-The ``wget`` command will download a program and run it.
-
 These installation instructions omit the optional dependency ``unpaper``, which is only available at version 0.4.2 in Ubuntu 14.04. The author could not find a backport of ``unpaper``, and created a .deb package to do the job of installing unpaper 6.1 (for x86 64-bit only):
 
 .. code-block:: bash
@@ -198,20 +258,22 @@ These installation instructions omit the optional dependency ``unpaper``, which
     wget -q 'https://www.dropbox.com/s/vaq0kbwi6e6au80/unpaper_6.1-1.deb?raw=1' -O unpaper_6.1-1.deb
     sudo dpkg -i unpaper_6.1-1.deb
 
-To add JBIG2 encoding, see `Installing the JBIG2 encoder`_.
+To add JBIG2 encoding, see :ref:`jbig2`.
 
-ArchLinux
-^^^^^^^^^
+ArchLinux (AUR)
+^^^^^^^^^^^^^^^
 
 .. image:: https://repology.org/badge/version-for-repo/aur/ocrmypdf.svg
     :alt: ArchLinux
     :target: https://repology.org/metapackage/ocrmypdf
 
-The author is aware of an `ArchLinux package for ocrmypdf <https://aur.archlinux.org/packages/ocrmypdf/>`_. It seems like the following command might work.
+There is an `ArchLinux User Repository package for ocrmypdf <https://aur.archlinux.org/packages/ocrmypdf/>`_. You can use the following command.
 
 .. code-block:: bash
 
-    pacman -S ocrmypdf
+    yaourt -S ocrmypdf
+
+If you have any difficulties with installation, check the repository package page.
 
 Other Linux packages
 ^^^^^^^^^^^^^^^^^^^^
@@ -336,6 +398,9 @@ Assuming you have a Docker engine running, you can download one of the three ava
     *   - ocrmypdf-polyglot
         - ``docker pull jbarlow83/ocrmypdf-polyglot``
         - As above, with all available language packs.
+    *   - ocrmypdf-webservice
+        - ``docker pull jbarlow83/ocrmypdf-webservice``
+        - All language packs, and a simple HTTP wrapper allowing OCRmyPDF to be used as a web service. Note that this component is licensed under AGPLv3.
 
 For example:
 
@@ -447,28 +512,26 @@ Since ``pip3 install --user`` does not work correctly on some platforms, notably
 Requirements for pip and HEAD install
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-OCRmyPDF currently requires these external programs and libraries to be installed:
+OCRmyPDF currently requires these external programs and libraries to be installed, and must be satisfied using the operating system package manager. ``pip`` cannot provide them.
 
-- Python 3.5 or newer
+- Python 3.6 or newer
 - Ghostscript 9.15 or newer
-- libexempi3 2.2.0 or newer
-- qpdf 7.0.0 or newer
-- Tesseract 3.04 or newer
+- qpdf 8.1.0 or newer
+- Tesseract 4.0.0-alpha or newer
 
-As of ocrmypdf 7.0.0, the following versions are recommended:
+As of ocrmypdf 7.2.1, the following versions are recommended:
 
 - Python 3.7
-- Ghostscript 9.23
-- libexempi3 2.4.5
-- qpdf 8.1.0
-- Tesseract 4.0.0-beta1
+- Ghostscript 9.23 or newer
+- qpdf 8.2.1
+- Tesseract 4.0.0 or newer
 - jbig2enc 0.29 or newer
 - pngquant 2.5 or newer
 - unpaper 6.1
 
 jbig2enc, pngquant, and unpaper are optional. If missing certain features are disabled. OCRmyPDF will discover them as soon as they are available.
 
-**jbig2enc**, if present, will be used to optimize the encoding of monochrome images.  This can significantly reduce the file size of the output file.  It is not required.  `jbig2enc <https://github.com/agl/jbig2enc>`_ is not generally available for Ubuntu or Debian due to lingering concerns about patent issues, but can easily be built from source. To add JBIG2 encoding, see `Optional: installing the JBIG2 encoder`_.
+**jbig2enc**, if present, will be used to optimize the encoding of monochrome images.  This can significantly reduce the file size of the output file.  It is not required.  `jbig2enc <https://github.com/agl/jbig2enc>`_ is not generally available for Ubuntu or Debian due to lingering concerns about patent issues, but can easily be built from source. To add JBIG2 encoding, see :ref:`jbig2`.
 
 **pngquant**, if present, is optionally used to optimize the encoding of PNG-style images in PDFs (actually, any that are that losslessly encoded) by lossily quantizing to a smaller color palette. It is only activated then the ``--optimize`` argument is ``2`` or ``3``.
 
@@ -476,13 +539,13 @@ jbig2enc, pngquant, and unpaper are optional. If missing certain features are di
 
 These are in addition to the Python packaging dependencies, meaning that unfortunately, the ``pip install`` command cannot satisfy all of them.
 
-Python 3.7 and Tesseract 4.0.0-beta.1 are recommended for best OCR results and best performance.
-
 
 Installing HEAD revision from sources
 -------------------------------------
 
-If you have ``git`` and Python 3.5 or newer installed, you can install from source. When the ``pip`` installer runs, it will alert you if dependencies are missing.
+If you have ``git`` and Python 3.6 or newer installed, you can install from source. When the ``pip`` installer runs, it will alert you if dependencies are missing.
+
+If you prefer to build every from source, you will need to `build pikepdf from source <https://pikepdf.readthedocs.io/en/latest/installation.html#building-from-source>`_. First ensure you can build and install pikepdf.
 
 To install the HEAD revision from sources in the current Python 3 environment:
 
@@ -532,6 +595,6 @@ To install all of the development and test requirements:
     source venv/bin/activate
     cd OCRmyPDF
     pip install -e .
-    pip install -r dev_requirements.txt -r test_requirements.txt
+    pip install -r requirements/dev.txt -r requirements/test.txt
 
-To add JBIG2 encoding, see `Installing the JBIG2 encoder`_.
+To add JBIG2 encoding, see :ref:`jbig2`.

docs/introduction.rst

@@ -64,7 +64,7 @@ In the case of a PDF that is nothing other than a container of images (no rotati
 
 OCRmyPDF uses several strategies depending on input options and the input PDF itself, but generally speaking it rasterizes a page for OCR and then grafts the OCR back onto the original. As such it can handle complex PDFs and still preserve their contents as much as possible.
 
-OCRmyPDF also supports a many, many edge cases that have cropped over several years of development. We support PDF features like images inside of Form XObjects, and pages with UserUnit scaling. We support rare image formats like non-monochrome 1-bit images. Thanks to pikepdf and QPDF, we auto-repair PDFs that are damaged. (Not that you need to know what any of these are! You should be able to throw any PDF at it.)
+OCRmyPDF also supports a many, many edge cases that have cropped over several years of development. We support PDF features like images inside of Form XObjects, and pages with UserUnit scaling. We support rare image formats like non-monochrome 1-bit images. We warn about files you may not to OCR. Thanks to pikepdf and QPDF, we auto-repair PDFs that are damaged. (Not that you need to know what any of these are! You should be able to throw any PDF at it.)
 
 
 Limitations
@@ -76,20 +76,21 @@ OCRmyPDF is limited by the Tesseract OCR engine.  As such it experiences these l
 * It is not capable of recognizing handwriting.
 * It may find gibberish and report this as OCR output.
 * If a document contains languages outside of those given in the ``-l LANG`` arguments, results may be poor.
-* It is not always good at analyzing the natural reading order of documents. For example, it may fail to recognize that a document contains two columns and join text across the columns.
+* It is not always good at analyzing the natural reading order of documents. For example, it may fail to recognize that a document contains two columns, and may try to join text across columns.
 * Poor quality scans may produce poor quality OCR. Garbage in, garbage out.
 * It does not expose information about what font family text belongs to.
 
 OCRmyPDF is also limited by the PDF specification:
 
 * PDF encodes the position of text glyphs but does not encode document structure.  There is no markup that divides a document in sections, paragraphs, sentences, or even words (since blank spaces are not represented). As such all elements of document structure including the spaces between words must be derived heuristically.  Some PDF viewers do a better job of this than others.
-* Because some popular open source PDF viewers have a particularly hard time with spaces betweem words, OCRmyPDF appends a space to each text element as a workaround. While this mixes document structure with graphical information that ideally should be left to the PDF viewer to interpret, it improves compatibility with some viewers and does not cause problems for better ones.
+* Because some popular open source PDF viewers have a particularly hard time with spaces betweem words, OCRmyPDF appends a space to each text element as a workaround (when using ``--pdf-renderer hocr``). While this mixes document structure with graphical information that ideally should be left to the PDF viewer to interpret, it improves compatibility with some viewers and does not cause problems for better ones.
 
 Ghostscript also imposes some limitations:
 
 * PDFs containing JBIG2-encoded content will be converted to CCITT Group4 encoding, which has lower compression ratios, if Ghostscript PDF/A is enabled.
 * PDFs containing JPEG 2000-encoded content will be converted to JPEG encoding, which may introduce compression artifacts, if Ghostscript PDF/A is enabled.
-* Ghostscript may transcode grayscale and color images, either lossy to lossless or lossless to lossy, based on an internal algorithm. This behavior can be suppressed by setting ``--pdfa-image-compression`` to ``jpeg`` or ``lossless`` to set all images to one type or the other. Ghostscript has no option to maintain the input image's format.
+* Ghostscript may transcode grayscale and color images, either lossy to lossless or lossless to lossy, based on an internal algorithm. This behavior can be suppressed by setting ``--pdfa-image-compression`` to ``jpeg`` or ``lossless`` to set all images to one type or the other. Ghostscript has no option to maintain the input image's format. (Ghostscript 9.25+ can copy JPEG images without transcoding them; earlier versions will transcode.)
+* Ghostscript's PDF/A conversion removes any XMP metadata that is not one of the standard XMP metadata namespaces for PDFs. In particular, PRISM Metdata is removed.
 
 Regarding OCRmyPDF itself:
 
@@ -109,7 +110,10 @@ To the author's knowledge, OCRmyPDF is the most feature-rich and thoroughly test
 Web front-ends
 --------------
 
-* `Nextcloud OCR <https://github.com/janis91/ocr>`_ is a free software plugin for the Nextcloud private cloud software
-* `OCRmyPDF-web <https://github.com/sseemayer/OCRmyPDF-web>`_, a micro web-frontend for OCRmyPDF (third-party, not actively maintained)
+The Docker image ocrmypdf-webservice provides a web service front-end that allows files to submitted over HTTP and the results "downloaded". This is an HTTP server intended to simplify web services deployments; it is not intended to be deployed on the public internet and no real security measures to speak of.
 
-Bear in mind that OCRmyPDF is not designed to be secure against malware-bearing PDFs (see `Using OCRmyPDF online`_).
+In addition, the following integrations are available:
+
+* `Nextcloud OCR <https://github.com/janis91/ocr>`_ is a free software plugin for the Nextcloud private cloud software
+
+Bear in mind that OCRmyPDF is not designed to be secure against malware-bearing PDFs (see `Using OCRmyPDF online`_). Users should ensure they comply with OCRmyPDF's licenses and the licenses of all dependencies. In particular, OCRmyPDF requires Ghostscript, which is licensed under AGPLv3.

docs/jbig2.rst

@@ -1,5 +1,7 @@
-Installing a JBIG2 encoder
-==========================
+.. _jbig2:
+
+Installing the JBIG2 encoder
+============================
 
 Most Linux distributions do not include a JBIG2 encoder since JBIG2 encoding was patented for a long time. All known JBIG2 US patents have expired as of 2017, but it is possible that unknown patents exist.
 
@@ -18,3 +20,16 @@ For all other Linux, you must build a JBIG2 encoder from source:
     ./autogen.sh
     ./configure && make
     [sudo] make install
+
+.. _jbig2-lossy:
+
+Lossy mode JBIG2
+----------------
+
+OCRmyPDF provides lossy mode JBIG2 as an advanced feature. Users should `review the technical concerns with JBIG2 in lossy mode <https://abbyy.technology/en:kb:tip:jbig2_compression_and_ocr>`_ and decide if this feature is acceptable for their use case.
+
+JBIG2 lossy mode does achieve higher compression ratios than any other monochrome (bitonal) compression technology; for large text documents the savings are considerable. JBIG2 lossless still gives great compression ratios and is a major improvement over the older CCITT G4 standard. As explained above, there is some risk of substitution errors.
+
+To turn on JBIG2 lossy mode, add the argument ``--jbig2-lossy``. ``--optimize {1,2,3}`` are necessary for the argument to take effect also required. Also, a JBIG2 encoder must be installed as described in the previous section.
+
+*ocrmypdf v7.0 and v7.1 used lossy mode by default.*

docs/languages.rst

@@ -17,12 +17,27 @@ Debian and Ubuntu users
    # Display a list of all Tesseract language packs
    apt-cache search tesseract-ocr
 
-   # Debian/Ubuntu users
-   apt-get install tesseract-ocr-chi-sim  # Example: Install Chinese Simplified language back
-   
+   # Install Chinese Simplified language pack
+   apt-get install tesseract-ocr-chi-sim
+
 You can then pass the ``-l LANG`` argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple
 languages can be requested using either ``-l eng+fre`` (English and French) or ``-l eng -l fre``.
 
+Fedora users
+------------
+
+.. code-block:: bash
+
+   # Display a list of all Tesseract language packs
+   dnf search tesseract
+
+   # Install Chinese Simplified language pack
+   dnf install tesseract-langpack-chi_sim
+
+You can then pass the ``-l LANG`` argument to OCRmyPDF to give a hint as to
+what languages it should search for. Multiple languages can be requested using
+either ``-l eng+fre`` (English and French) or ``-l eng -l fre``.
+
 macOS users
 -----------
 

docs/release_notes.rst

@@ -13,6 +13,188 @@ Note that it is licensed under GPLv3, so scripts that ``import ocrmypdf`` and ar
    find:    [^`]\#([0-9]{1,3})[^0-9]
    replace: `#$1 <https://github.com/jbarlow83/OCRmyPDF/issues/$1>`_
 
+v8.1.0
+------
+
+-   Added a feature, ``--unpaper-args``, which allows passing arbitrary arguments to ``unpaper`` when using ``--clean`` or ``--clean-final``. The default, very conservative unpaper settings are suppressed.
+
+-   The argument ``--clean-final`` now implies ``--clean``. It was possible to issue ``--clean-final`` on its before this, but it would have no useful effect.
+
+-   Fixed an exception on traversing corrupt table of contents entries (specifically, those with invalid destination objects)
+
+-   Fixed an issue when using ``--tesseract-timeout`` and image processing features on a file with more than 100 pages. `#347 <https://github.com/jbarlow83/OCRmyPDF/issues/347>`_
+
+-   OCRmyPDF now always calls ``os.nice(5)`` to signal to operating systems that it is a background process.
+
+v8.0.1
+------
+
+-   Fixed an exception when parsing PDFs that are missing a required field. `#325 <https://github.com/jbarlow83/OCRmyPDF/issues/325>`_
+
+-   pikepdf 1.0.5 is now required, to address some other PDF parsing issues.
+
+v8.0.0
+------
+
+No major features. The intent of this release is to sever support for older versions of certain dependencies.
+
+**Breaking changes**
+
+-   Dropped support for Tesseract 3.x. Tesseract 4.0 or newer is now required.
+
+-   Dropped support for Python 3.5.
+
+-   Some ``ocrmypdf.pdfa`` APIs that were deprecated in v7.x were removed. This functionality has been moved to pikepdf.
+
+**Other changes**
+
+-   Fixed an unhandled exception when attempting to mask barcodes. `#322 <https://github.com/jbarlow83/OCRmyPDF/issues/322>`_
+
+-   It is now possible to use ocrmypdf without pdfminer.six, to support distributions that do not have it or cannot currently use it (e.g. Homebrew). Downstream maintainers should include pdfminer.six if possible.
+
+-   A warning is now issue when PDF/A conversion removes some XMP metadata from the input PDF. (Only a "whitelist" of certain XMP metadata types are allowed in PDF/A.)
+
+-   Fixed several issues that caused PDF/As to be produced with nonconforming XMP metadata (would fail validation with veraPDF).
+
+-   Fixed some instances where invalid DocumentInfo from a PDF cause XMP metadata creation to fail.
+
+-   Fixed a few documentation problems.
+
+-   pikepdf 1.0.2 is now required.
+
+v7.4.0
+------
+
+-   ``--force-ocr`` may now be used with the new ``--threshold`` and ``--mask-barcodes`` features
+
+-   pikepdf >= 0.9.1 is now required.
+
+-   Changed metadata handling to pikepdf 0.9.1. As a result, metadata handling of non-ASCII characters in Ghostscript 9.25 or later is fixed.
+
+-   chardet >= 3.0.4 is temporarily listed as required. pdfminer.six depends on it, but the most recent release does not specify this requirement. (`#326 <https://github.com/jbarlow83/OCRmyPDF/issues/326>`_)
+
+-   python-xmp-toolkit and libexempi are no longer required.
+
+-   A new Docker image is now being provided for users who wish to access OCRmyPDF over a simple HTTP interface, instead of the command line.
+
+-   Increase tolerance of PDFs that overflow or underflow the PDF graphics stack. (`#325 <https://github.com/jbarlow83/OCRmyPDF/issues/325>`_)
+
+v7.3.1
+------
+
+-   Fixed performance regression from v7.3.0; fast page analysis was not selected when it should be.
+
+-   Fixed a few exceptions related to the new ``--mask-barcodes`` feature and improved argument checking
+
+-   Added missing detection of TrueType fonts that lack a Unicode mapping
+
+
+v7.3.0
+------
+
+-   Added a new feature ``--redo-ocr`` to detect existing OCR in a file, remove it, and redo the OCR. This may be particularly helpful for anyone who wants to take advantage of OCR quality improvements in Tesseract 4.0. Note that OCR added by OCRmyPDF before version 3.0 cannot be detected since it was not properly marked as invisible text in the earliest versions. OCR that constructs a font from visible text, such as Adobe Acrobat's ClearScan.
+
+-   OCRmyPDF's content detection is generally more sophisticated. It learns more about the contents of each PDF and makes better recommendations:
+
+    -   OCRmyPDF can now detect when a PDF contains text that cannot be mapped to Unicode (meaning it is readable to human eyes but copy-pastes as gibberish). In these cases it recommends ``--force-ocr`` to make the text searchable.
+
+    -   PDFs containing vector objects are now rendered at more appropriate resolution for OCR.
+
+    -   We now exit with an error for PDFs that contain Adobe LiveCycle Designer's dynamic XFA forms. Currently the open source community does not have tools to work with these files.
+
+    -   OCRmyPDF now warns when a PDF that contains Adobe AcroForms, since such files probably do not need OCR. It can work with these files.
+
+-   Added three new **experimental** features to improve OCR quality in certain conditions. The name, syntax and behavior of these arguments is subject to change. They may also be incompatible with some other features.
+
+    -   ``--remove-vectors`` which strips out vector graphics. This can improve OCR quality since OCR will not search artwork for readable text; however, it currently removes "text as curves" as well.
+
+    -   ``--mask-barcodes`` to detect and suppress barcodes in files. We have observed that barcodes can interfere with OCR because they are "text-like" but not actually textual.
+
+    -   ``--threshold`` which uses a more sophisticated thresholding algorithm than is currently in use in Tesseract OCR. This works around a `known issue in Tesseract 4.0 <https://github.com/tesseract-ocr/tesseract/issues/1990>`_ with dark text on bright backgrounds.
+
+-   Fixed an issue where an error message was not reported when the installed Ghostscript was very old.
+
+-   The PDF optimizer now saves files with object streams enabled when the optimization level is ``--optimize 1`` or higher (the default). This makes files a little bit smaller, but requires PDF 1.5. PDF 1.5 was first released in 2003 and is broadly supported by PDF viewers, but some rudimentary PDF parsers such as PyPDF2 do not understand object streams. You can use the command line tool ``qpdf --object-streams=disable`` or `pikepdf <https://github.com/pikepdf/pikepdf>`_ library to remove them.
+
+-   New dependency: pdfminer.six 20181108. Note this is a fork of the Python 2-only pdfminer.
+
+-   Deprecation notice: At the end of 2018, we will be ending support for Python 3.5 and Tesseract 3.x. OCRmyPDF v7 will continue to work with older versions.
+
+v7.2.1
+------
+
+-   Fix compatibility with an API change in pikepdf 0.3.5.
+
+-   A kludge to support Leptonica versions older than 1.72 in the test suite was dropped. Older versions of Leptonica are likely still compatible. The only impact is that a portion of the test suite will be skipped.
+
+
+v7.2.0
+------
+
+**Lossy JBIG2 behavior change**
+
+A user reported that ocrmypdf was in fact using JBIG2 in **lossy** compression mode. This was not the intended behavior. Users should `review the technical concerns with JBIG2 in lossy mode <https://abbyy.technology/en:kb:tip:jbig2_compression_and_ocr>`_ and decide if this is a concern for their use case.
+
+JBIG2 lossy mode does achieve higher compression ratios than any other monochrome compression technology; for large text documents the savings are considerable. JBIG2 lossless still gives great compression ratios and is a major improvement over the older CCITT G4 standard.
+
+Only users who have reviewed the concerns with JBIG2 in lossy mode should opt-in. As such, lossy mode JBIG2 is only turned on when the new argument ``--jbig2-lossy`` is issued. This is independent of the setting for ``--optimize``.
+
+Users who did not install an optional JBIG2 encoder are unaffected.
+
+(Thanks to user 'bsdice' for reporting this issue.)
+
+**Other issues**
+
+-   When the image optimizer quantizes an image to 1 bit per pixel, it will now attempt to further optimize that image as CCITT or JBIG2, instead of keeping it in the "flate" encoding which is not efficient for 1 bpp images. (`#297 <https://github.com/jbarlow83/OCRmyPDF/issues/297>`_)
+
+-   Images in PDFs that are used as soft masks (i.e. transparency masks or alpha channels) are now excluded from optimization.
+
+-   Fixed handling of Tesseract 4.0-rc1 which now accepts invalid Tesseract configuration files, which broke the test suite.
+
+v7.1.0
+------
+
+-   Improve the performance of initial text extraction, which is done to determine if a file contains existing text of some kind or not. On large files, this initial processing is now about 20x times faster. (`#299 <https://github.com/jbarlow83/OCRmyPDF/issues/299>`_)
+
+-   pikepdf 0.3.3 is now required.
+
+-   Fixed issue `#231 <https://github.com/jbarlow83/OCRmyPDF/issues/231>`_, a problem with JPEG2000 images where image metadata was only available inside the JPEG2000 file.
+
+-   Fixed some additional Ghostscript 9.25 compatibility issues.
+
+-   Improved handling of KeyboardInterrupt error messages. (`#301 <https://github.com/jbarlow83/OCRmyPDF/issues/301>`_)
+
+-   README.md is now served in GitHub markdown instead of reStructuredText.
+
+v7.0.6
+------
+
+-   Blacklist Ghostscript 9.24, now that 9.25 is available and fixes many regressions in 9.24.
+
+
+v7.0.5
+------
+
+-   Improve capability with Ghostscript 9.24, and enable the JPEG passthrough feature when this version in installed.
+
+-   Ghostscript 9.24 lost the ability to set PDF title, author, subject and keyword metadata to Unicode strings. OCRmyPDF will set ASCII strings and warn when Unicode is suppressed. Other software may be used to update metadata. This is a short term work around.
+
+-   PDFs generated by Kodak Capture Desktop, or generally PDFs that contain indirect references to null objects in their table of contents, would have an invalid table of contents after processing by OCRmyPDF that might interfere with other viewers. This has been fixed.
+
+-   Detect PDFs generated by Adobe LiveCycle, which can only be displayed in Adobe Acrobat and Reader currently. When these are encountered, exit with an error instead of performing OCR on the "Please wait" error message page.
+
+v7.0.4
+------
+
+-   Fix exception thrown when trying to optimize a certain type of PNG embedded in a PDF with the ``-O2``
+
+-   Update to pikepdf 0.3.2, to gain support for optimizing some additional image types that were previously excluded from optimization (CMYK and grayscale). Fixes `#285 <https://github.com/jbarlow83/OCRmyPDF/issues/285>`_.
+
+v7.0.3
+------
+
+-   Fix issue `#284 <https://github.com/jbarlow83/OCRmyPDF/issues/284>`_, an error when parsing inline images that have are also image masks, by upgrading pikepdf to 0.3.1
+
 v7.0.2
 ------
 
@@ -76,10 +258,27 @@ v7.0.0
 
     +   It may be necessary to separately ``pip install pycparser`` to avoid `another Python 3.7 issue <https://github.com/eliben/pycparser/pull/135>`_.
 
+v6.2.5
+------
+
+-   Disable a failing test due to Tesseract 4.0rc1 behavior change. Previously, Tesseract would exit with an error message if its configuration was invalid, and OCRmyPDF would intercept this message. Now Tesseract issues a warning, which OCRmyPDF v6.2.5 may relay or ignore. (In v7.x, OCRmyPDF will respond to the warning.)
+
+-   This release branch no longer supports using the optional PyMuPDF installation, since it was removed in v7.x.
+
+-   This release branch no longer supports macOS. macOS users should upgrade to v7.x.
+
+v6.2.4
+------
+
+-   Backport Ghostscript 9.25 compatibility fixes, which removes support for setting Unicode metadata
+-   Backport blacklisting Ghostscript 9.24
+-   Older versions of Ghostscript are still supported
+
 v6.2.3
 ------
 
 -   Fix compatibility with img2pdf >= 0.3.0 by rejecting input images that have an alpha channel
+-   This version will be included in Ubuntu 18.10
 
 v6.2.2
 ------
@@ -342,7 +541,6 @@ v5.0.1
 
 -   Fixed issue `#169 <https://github.com/jbarlow83/OCRmyPDF/issues/169>`_, exception due to failure to create sidecar text files on some versions of Tesseract 3.04, including the jbarlow83/ocrmypdf Docker image
 
-
 v5.0
 ----
 
@@ -358,7 +556,6 @@ v5.0
 -   Fixed issue `#164 <https://github.com/jbarlow83/OCRmyPDF/issues/164>`_, a typo
 -   Removed the command line parameters ``-n`` and ``--just-print`` since they have not worked for some time (reported as Ubuntu bug `#1687308 <https://bugs.launchpad.net/ubuntu/+source/ocrmypdf/+bug/1687308>`_)
 
-
 v4.5.6
 ------
 
@@ -366,21 +563,18 @@ v4.5.6
 -   Fixed issue `#158 <https://github.com/jbarlow83/OCRmyPDF/issues/158>`_, ocrmypdf now stops and terminates if Ghostscript fails on an intermediate step, as it is not possible to proceed.
 -   Fixed issue `#160 <https://github.com/jbarlow83/OCRmyPDF/issues/160>`_, exception thrown on certain invalid arguments instead of error message
 
-
 v4.5.5
 ------
 
 -   Automated update of macOS homebrew tap
 -   Fixed issue `#154 <https://github.com/jbarlow83/OCRmyPDF/issues/154>`_, KeyError '/Contents' when searching for text on blank pages that have no /Contents record.  Note: incomplete fix for this issue.
 
-
 v4.5.4
 ------
 
 -   Fix ``--skip-big`` raising an exception if a page contains no images (`#152 <https://github.com/jbarlow83/OCRmyPDF/issues/152>`_) (thanks to @TomRaz)
 -   Fix an issue where pages with no images might trigger "cannot write mode P as JPEG" (`#151 <https://github.com/jbarlow83/OCRmyPDF/issues/151>`_)
 
-
 v4.5.3
 ------
 
@@ -389,7 +583,6 @@ v4.5.3
 -   Fixed an issue where the ``tess4`` renderer would duplicate content onto output pages if tesseract failed or timed out
 -   Fixed ``tess4`` renderer not recognized when lossless reconstruction is possible
 
-
 v4.5.2
 ------
 
@@ -397,21 +590,18 @@ v4.5.2
 -   Make "using Tesseract 4.0" warning less ominous
 -   Set up machinery for homebrew OCRmyPDF tap
 
-
 v4.5.1
 ------
 
 -   Fix issue `#137 <https://github.com/jbarlow83/OCRmyPDF/issues/137>`_, proportions of images with a non-square pixel aspect ratio would be distorted in output for ``--force-ocr`` and some other combinations of flags
 
-
 v4.5
 ----
 
--   Exotic PDFs containing "Form XObjects" are now supported (issue `#134 <https://github.com/jbarlow83/OCRmyPDF/issues/134>`_; PDF reference manual 8.10), and images they contain are taken into account when determining the resolution for rasterizing
+-   PDFs containing "Form XObjects" are now supported (issue `#134 <https://github.com/jbarlow83/OCRmyPDF/issues/134>`_; PDF reference manual 8.10), and images they contain are taken into account when determining the resolution for rasterizing
 -   The Tesseract 4 Docker image no longer includes all languages, because it took so long to build something would tend to fail
 -   OCRmyPDF now warns about using ``--pdf-renderer tesseract`` with Tesseract 3.04 or lower due to issues with Ghostscript corrupting the OCR text in these cases
 
-
 v4.4.2
 ------
 
@@ -422,7 +612,6 @@ v4.4.2
 
 -   OCRmyPDF now prevents running the Tesseract 4 renderer with Tesseract 3.04, which was permitted in v4.4 and v4.4.1 but will not work
 
-
 v4.4.1
 ------
 
@@ -449,32 +638,27 @@ v4.4
 
     + However, OCRmyPDF's dependency "ruffus" is not re-entrant, so no Python API is available. Scripts should continue to use the command line interface.
 
-
 v4.3.5
 ------
 
 -   Update documentation to confirm Python 3.6.0 compatibility. No code changes were needed, so many earlier versions are likely supported.
 
-
 v4.3.4
 ------
 
 -   Fixed "decimal.InvalidOperation: quantize result has too many digits" for high DPI images
 
-
 v4.3.3
 ------
 
 -   Fixed PDF/A creation with Ghostscript 9.20 properly
 -   Fixed an exception on inline stencil masks with a missing optional parameter
 
-
 v4.3.2
 ------
 
 -   Fixed a PDF/A creation issue with Ghostscript 9.20 (note: this fix did not actually work)
 
-
 v4.3.1
 ------
 
@@ -485,7 +669,6 @@ v4.3.1
 -   Cleaned up debug output
 -   Tesseract caching in test cases is now more cautious about false cache hits and reproducing exact output, not that any problems were observed
 
-
 v4.3
 ----
 
@@ -503,7 +686,6 @@ v4.2.5
 -   Fixed an issue (`#100 <https://github.com/jbarlow83/OCRmyPDF/issues/100>`_) with PDFs that omit the optional /BitsPerComponent parameter on images
 -   Removed non-free file milk.pdf
 
-
 v4.2.4
 ------
 
@@ -523,20 +705,17 @@ v4.2.3
 -   Added a test case for indirect objects and linearized PDFs
 -   Deprecated the OCRmyPDF.sh shell script
 
-
 v4.2.2
 ------
 
 -   Improvements to documentation
 
-
 v4.2.1
 ------
 
 -   Fixed an issue where PDF pages that contained stencil masks would report an incorrect DPI and cause Ghostscript to abort
 -   Implemented stdin streaming
 
-
 v4.2
 ----
 
@@ -575,7 +754,6 @@ v4.1.4
 
 -   Bug fix: monochrome images with an ICC profile attached were incorrectly converted to full color images if lossless reconstruction was not possible due to other settings; consequence was increased file size for these images
 
-
 v4.1.3
 ------
 
@@ -584,14 +762,12 @@ v4.1.3
 -   Fix order of operations for matrix multiplication (no effect on most users)
 -   Add a few leptonica wrapper functions (no effect on most users)
 
-
 v4.1.2
 ------
 
 -   Replace IEC sRGB ICC profile with Debian's sRGB (from icc-profiles-free) which is more compatible with the MIT license
 -   More helpful error message for an error related to certain types of malformed PDFs
 
-
 v4.1
 ----
 
@@ -599,20 +775,17 @@ v4.1
 -   Fixed problems in error checking if ``unpaper`` is uninstalled or missing at run-time
 -   Fixed problems with "RethrownJobError" errors during error handling that suppressed the useful error messages
 
-
 v4.0.7
 ------
 
 -   Minor correction to Ghostscript output settings
 
-
 v4.0.6
 ------
 
 -   Update install instructions
 -   Provide a sRGB profile instead of using Ghostscript's
 
-
 v4.0.5
 ------
 
@@ -626,18 +799,14 @@ v4.0.4
 
 Released with verbose debug message turned on. Do not use. Skip to v4.0.5.
 
-
 v4.0.3
 ------
 
 New features
-^^^^^^^^^^^^
 
 -   Page orientations detected are now reported in a summary comment
 
-
 Fixes
-^^^^^
 
 -   Show stack trace if unexpected errors occur
 -   Treat "too few characters" error message from Tesseract as a reason to skip that page rather than
@@ -649,7 +818,7 @@ v4.0.2
 ------
 
 Fixes
-^^^^^
+
 
 -   Fixed compatibility with Tesseract 3.04.01 release, particularly its different way of outputting
     orientation information
@@ -661,7 +830,7 @@ v4.0.1
 ------
 
 Fixes
-^^^^^
+
 
 -   Fixed a KeyError if tesseract fails to find page orientation information
 
@@ -670,7 +839,6 @@ v4.0
 ----
 
 New features
-^^^^^^^^^^^^
 
 -   Automatic page rotation (``-r``) is now available. It uses ignores any prior rotation information
     on PDFs and sets rotation based on the dominant orientation of detectable text. This feature is
@@ -680,7 +848,6 @@ New features
 
 
 Fixes
-^^^^^
 
 -   Fixed an issue where lossless reconstruction could cause some pages to be appear incorrectly
     if the page was rotated by the user in Acrobat after being scanned (specifically if it a /Rotate tag)
@@ -689,7 +856,6 @@ Fixes
 
 
 Changes
-^^^^^^^
 
 -   Logging output is now much easier to read
 -   ``--deskew`` is now performed by Leptonica instead of unpaper (`#25 <https://github.com/jbarlow83/OCRmyPDF/issues/25>`_)
@@ -705,7 +871,6 @@ v3.2.1
 ------
 
 Changes
-^^^^^^^
 
 -   Fixed issue `#47 <https://github.com/jbarlow83/OCRmyPDF/issues/47>`_ "convert() got and unexpected keyword argument 'dpi'" by upgrading to img2pdf 0.2
 -   Tweaked the Dockerfiles
@@ -715,7 +880,6 @@ v3.2
 ----
 
 New features
-^^^^^^^^^^^^
 
 -   Lossless reconstruction: when possible, OCRmyPDF will inject text layers without
     otherwise manipulating the content and layout of a PDF page. For example, a PDF containing a mix
@@ -727,7 +891,6 @@ New features
     for the polyglots among us. It is much larger.
 
 Changes
-^^^^^^^
 
 -   JPEG transcoding quality is now 95 instead of the default 75. Bigger file sizes for less degradation.
 
@@ -737,7 +900,6 @@ v3.1.1
 ------
 
 Changes
-^^^^^^^
 
 -   Fixed bug that caused incorrect page size and DPI calculations on documents with mixed page sizes
 
@@ -745,7 +907,6 @@ v3.1
 ----
 
 Changes
-^^^^^^^
 
 -   Default output format is now PDF/A-2b instead of PDF/A-1b
 -   Python 3.5 and macOS El Capitan are now supported platforms - no changes were
@@ -763,7 +924,6 @@ v3.0
 ----
 
 New features
-^^^^^^^^^^^^
 
 -   Easier installation with a Docker container or Python's ``pip`` package manager
 -   Eliminated many external dependencies, so it's easier to setup
@@ -786,7 +946,6 @@ New features
 -   Multiple images on the same PDF page are now supported
 
 Changes
-^^^^^^^
 
 -   New, robust rewrite in Python 3.4+ with ruffus_ pipelines
 -   Now uses Ghostscript 9.14's improved color conversion model to preserve PDF colors
@@ -823,8 +982,7 @@ Changes
 .. _Unpaper: https://github.com/Flameeyes/unpaper
 .. _JHOVE: http://jhove.sourceforge.net/
 
-Release candidates
-^^^^^^^^^^^^^^^^^^
+Release candidates^
 
 -   rc9:
 
@@ -892,12 +1050,11 @@ where ``settings.txt`` contains *one argument per line*, for example:
 
 
 Fixes
-^^^^^
+
 
 -   Handling of filenames containing spaces: fixed
 
 Notes and known issues
-^^^^^^^^^^^^^^^^^^^^^^
 
 -   Some dependencies may work with lower versions than tested, so try
     overriding dependencies if they are "in the way" to see if they work.

misc/completions.fish

@@ -0,0 +1,70 @@
+complete -c ocrmypdf -l version
+complete -c ocrmypdf -l help
+
+complete -c ocrmypdf -l sidecar -r -d "write OCR to text file"
+complete -c ocrmypdf -s q -l quiet
+
+complete -c ocrmypdf -s r -l rotate-pages -d "rotate pages to correct orientation"
+complete -c ocrmypdf -s d -l deskew -d "fix small horizontal alignment skew"
+complete -c ocrmypdf -s c -l clean -d "clean document images before OCR"
+complete -c ocrmypdf -s i -l clean-final -d "clean document images and keep result"
+complete -c ocrmypdf -l remove-vectors -d "don't send vector objects to OCR"
+complete -c ocrmypdf -l mask-barcodes -d "mask barcodes from OCR"
+complete -c ocrmypdf -l threshold -d "threshold images before OCR"
+
+complete -c ocrmypdf -s f -l force-ocr -d "OCR documents that already have printable text"
+complete -c ocrmypdf -s s -l skip-ocr -d "skip OCR on pages that text, otherwise try OCR"
+complete -c ocrmypdf -l redo-ocr -d "redo OCR on any pages that seem to have OCR already"
+
+complete -c ocrmypdf -s k -l keep-temporary-files -d "keep temporary files (debug)"
+
+complete -c ocrmypdf -x -s l -l language -d 'language'
+complete -c ocrmypdf -x -s l -l language -a '(tesseract --list-langs)'
+
+complete -c ocrmypdf -x -l image-dpi -d "assume this DPI if input image DPI is unknown"
+
+function __fish_ocrmypdf_output_type
+    echo -e "pdfa\t"(_ "output a PDF/A (default)")
+    echo -e "pdf\t"(_ "output a standard PDF")
+    echo -e "pdfa-1\t"(_ "output a PDF/A-1b")
+    echo -e "pdfa-2\t"(_ "output a PDF/A-2b")
+    echo -e "pdfa-3\t"(_ "output a PDF/A-3b")
+end
+complete -c ocrmypdf -x -l output-type -a '(__fish_ocrmypdf_output_type)' -d "select PDF output options"
+
+function __fish_ocrmypdf_pdf_renderer
+    echo -e "auto\t"(_ "auto select PDF renderer")
+    echo -e "hocr\t"(_ "use hocr renderer")
+    echo -e "sandwich\t"(_ "use sandwich renderer")
+end
+complete -c ocrmypdf -x -l pdf-render -a '(__fish_ocrmypdf_pdf_renderer)' -d "select PDF renderer options"
+
+function __fish_ocrmypdf_optimize
+    echo -e "0\t"(_ "do not optimize")
+    echo -e "1\t"(_ "do safe, lossless optimizations (default)")
+    echo -e "2\t"(_ "do some lossy optimizations")
+    echo -e "3\t"(_ "do aggressive lossy optimizations (including lossy JBIG2)")
+end
+complete -c ocrmypdf -x -s O -l optimize -a '(__fish_ocrmypdf_optimize)' -d "select optimization level"
+
+complete -c ocrmypdf -x -s j -l jobs -d "how many worker processes to use"
+complete -c ocrmypdf -x -s v -a '(seq 1 9)'
+complete -c ocrmypdf -x -l title -d "set metadata"
+complete -c ocrmypdf -x -l author -d "set metadata"
+complete -c ocrmypdf -x -l subject -d "set metadata"
+complete -c ocrmypdf -x -l keywords -d "set metadata"
+complete -c ocrmypdf -x -l oversample -d "oversample images to this DPI"
+complete -c ocrmypdf -x -l skip-big -d "skip OCR on pages larger than this many MPixels"
+
+complete -c ocrmypdf -x -l jpeg-quality -d "JPEG quality [0..100]"
+complete -c ocrmypdf -x -l png-quality -d "PNG quality [0..100]"
+complete -c ocrmypdf -x -l jbig2-lossy -d "enable lossy JBIG2 (see docs)"
+complete -c ocrmypdf -x -l max-image-mpixels -d "image decompression bomb threshold"
+complete -c ocrmypdf -x -l tesseract-config -d "set custom tesseract config file"
+complete -c ocrmypdf -x -l tesseract-pagesegmode -d "set tesseract --psm"
+complete -c ocrmypdf -x -l tesseract-oem -d "set tesseract --oem"
+complete -c ocrmypdf -x -l tesseract-timeout -d "maximum number of seconds to wait for OCR"
+complete -c ocrmypdf -x -l rotate-pages-threshold -d "page rotation confidence"
+complete -c ocrmypdf -x -l pdfa-image-compression -a 'auto jpeg lossless' -d "set PDF/A image compression options"
+
+complete -c ocrmypdf -x -a "(__fish_complete_suffix .pdf)"

pyproject.toml

@@ -0,0 +1,22 @@
+[tool.black]
+line-length = 88
+py36 = true
+skip-string-normalization = true
+include = '\.pyi?$'
+exclude = '''
+/(
+    \.eggs
+  | \.git
+  | \.hg
+  | \.mypy_cache
+  | \.tox
+  | \.venv
+  | _build
+  | buck-out
+  | build
+  | dist
+  | docs
+  | misc
+  | \.egg-info
+)/
+'''

requirements/dev.txt

@@ -1,4 +1,4 @@
 check-manifest >= 0.35
 twine >= 1.8.1
-coverage >= 4.4
+coverage >= 4.5
 GitPython == 2.1.3

requirements/main.txt

@@ -1,11 +1,13 @@
 # requirements.txt can be used to replicate the developer's build environment
 # setup.py lists a separate set of requirements that are looser to simplify
 # installation
+chardet == 3.0.4
 cffi == 1.11.5
-img2pdf == 0.3.0
-pikepdf == 0.3.0
+img2pdf == 0.3.1
+pdfminer.six == 20181108
+pikepdf == 1.0.2
 Pillow >= 5.0.0, != 5.1.0 ; sys_platform == "darwin"
-pycparser == 2.18
+pycparser == 2.19
 python-xmp-toolkit == 2.0.1
-reportlab == 3.4.0
-ruffus == 2.7.0
+reportlab == 3.5.9
+ruffus == 2.8.0

requirements/test.txt

@@ -1,4 +1,4 @@
-pytest >= 3.2
+pytest == 3.9.3
 pytest-helpers-namespace
 pytest-xdist
 pytest-cov

setup.cfg

@@ -11,6 +11,15 @@ ignore =
 [tool:pytest]
 norecursedirs = lib .pc .git output cache resources
 testpaths = tests
+filterwarnings =
+	ignore:.*XMLParser.*:DeprecationWarning
+
+[isort]
+multi_line_output=3
+include_trailing_comma=True
+force_grid_wrap=0
+use_parentheses=True
+line_length=88
 
 [metadata]
-license_file = LICENSE
+license_file = LICENSE

setup.py

@@ -20,16 +20,16 @@
 from __future__ import print_function, unicode_literals
 
 import sys
-if sys.version_info < (3, 5):
-    print("Python 3.5 or newer is required", file=sys.stderr)
+if sys.version_info < (3, 6):
+    print("Python 3.6 or newer is required", file=sys.stderr)
     sys.exit(1)
 
-from setuptools import setup, find_packages  # nopep8
-from subprocess import STDOUT, check_output, CalledProcessError  # nopep8
-from collections.abc import Mapping  # nopep8
-import re  # nopep8
-import os  # nopep8
+from setuptools import setup, find_packages
+from subprocess import STDOUT, check_output, CalledProcessError
+from collections.abc import Mapping
+import re
 
+# pylint: disable=w0613
 
 missing_program = '''
 The program '{program}' could not be executed or was not found on your
@@ -132,12 +132,12 @@ def check_external_program(
         program,
         need_version,
         package,
-        version_check_args=['--version'],
+        version_check_args=None,
         version_scrape_regex=re.compile(r'(\d+\.\d+(?:\.\d+)?)'),
         optional=False):
-
-    print('Checking for {program} >= {need_version}...'.format(
-            program=program, need_version=need_version))
+    if not version_check_args:
+        version_check_args = ['--version']
+    print(f'Checking for {program} >= {need_version}...')
     try:
         result = check_output(
                 [program] + version_check_args,
@@ -146,7 +146,7 @@ def check_external_program(
         error_missing_program(program, package, optional)
         if not optional:
             sys.exit(1)
-        print('Continuing install without {program}'.format(program=program))
+        print(f'Continuing install without {program}')
         return
 
     try:
@@ -159,8 +159,7 @@ def check_external_program(
         error_old_version(program, package, optional, need_version,
                           found_version)
 
-    print('Found {program} {found_version}'.format(
-            program=program, found_version=found_version))
+    print(f'Found {program} {found_version}')
 
 
 command = next((arg for arg in sys.argv[1:] if not arg.startswith('-')), '')
@@ -171,7 +170,7 @@ if not forced and command.startswith('install') or \
         command in ['check', 'test', 'nosetests', 'easy_install']:
     check_external_program(
         program='tesseract',
-        need_version='3.04',  # using backport for Travis CI
+        need_version='4.0.0',  # using backport for Travis CI
         package={'darwin': 'tesseract', 'linux': 'tesseract-ocr'}
     )
     check_external_program(
@@ -201,17 +200,18 @@ if 'upload' in sys.argv[1:]:
     print('Use twine to upload the package - setup.py upload is insecure')
     sys.exit(1)
 
-tests_require = open('test_requirements.txt').read().splitlines()
+tests_require = open('requirements/test.txt', encoding='utf-8').read().splitlines()
 
 
 def readme():
-    with open('README.rst') as f:
+    with open('README.md', encoding='utf-8') as f:
         return f.read()
 
 setup(
     name='ocrmypdf',
     description='OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to be searched',
     long_description=readme(),
+    long_description_content_type='text/markdown',
     url='https://github.com/jbarlow83/OCRmyPDF',
     author='James R. Barlow',
     author_email='jim@purplerock.ca',
@@ -219,7 +219,6 @@ setup(
     package_dir={'': 'src'},
     keywords=['PDF', 'OCR', 'optical character recognition', 'PDF/A', 'scanning'],
     classifiers=[
-        "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Development Status :: 5 - Production/Stable",
@@ -236,29 +235,31 @@ setup(
         "Topic :: Text Processing :: Indexing",
         "Topic :: Text Processing :: Linguistic",
         ],
-    python_requires=' >= 3.5',
+    python_requires=' >= 3.6',
     setup_requires=[
         'cffi >= 1.9.1',        # to build the leptonica module
         'pytest-runner',        # to enable python setup.py test
         'setuptools_scm',       # so that version will work
+        'setuptools_scm_git_archive'    # enable version from github tarballs
     ],
     use_scm_version={'version_scheme': 'post-release'},
     cffi_modules=[
         'src/ocrmypdf/lib/compile_leptonica.py:ffibuilder'
     ],
     install_requires=[
+        'chardet >= 3.0.4, < 4',  # unlisted requirement of pdfminer.six 20181108
         'cffi >= 1.9.1',          # must be a setup and install requirement
-        'img2pdf >= 0.2.4, < 0.4',       # pure Python, so track HEAD closely
-        'pikepdf >= 0.2.2, < 0.4',
+        'img2pdf >= 0.3.0, < 0.4',       # pure Python, so track HEAD closely
+        'pdfminer.six == 20181108 ; sys_platform != "darwin"',
+        'pikepdf >= 1.0.5, < 2',
         'Pillow >= 4.0.0, != 5.1.0 ; sys_platform == "darwin"',
                                   # Pillow < 4 has BytesIO/TIFF bug w/img2pdf 0.2.3
                                   # block 5.1.0, broken wheels
-        'python-xmp-toolkit >= 2, < 3',
         'reportlab >= 3.3.0',     # oldest released version with sane image handling
         'ruffus >= 2.7.0',
     ],
     extras_require={
-        'fitz': [],  # Backward compatibility
+        'pdfminer': ['pdfminer.six == 20181108'],
     },
     tests_require=tests_require,
     entry_points={
@@ -268,4 +269,10 @@ setup(
     },
     package_data={'ocrmypdf': ['data/sRGB.icc']},
     include_package_data=True,
-    zip_safe=False)
+    zip_safe=False,
+    project_urls={
+        'Documentation': 'https://ocrmypdf.readthedocs.io/',
+        'Source': 'https://github.com/jbarlow83/ocrmypdf',
+        'Tracker': 'https://github.com/jbarlow83/ocrmypdf/issues'
+    }
+)

src/ocrmypdf/__init__.py

@@ -25,10 +25,18 @@ __version__ = pkg_resources.get_distribution('ocrmypdf').version
 VERSION = __version__
 
 from .exceptions import (
-    ExitCode, BadArgsError, PdfMergeFailedError, MissingDependencyError,
-    UnsupportedImageFormatError, DpiError, OutputFileAccessError,
-    PriorOcrFoundError, InputFileError, SubprocessOutputError,
-    EncryptedPdfError, TesseractConfigError
+    ExitCode,
+    BadArgsError,
+    PdfMergeFailedError,
+    MissingDependencyError,
+    UnsupportedImageFormatError,
+    DpiError,
+    OutputFileAccessError,
+    PriorOcrFoundError,
+    InputFileError,
+    SubprocessOutputError,
+    EncryptedPdfError,
+    TesseractConfigError,
 )
 
 from . import helpers

src/ocrmypdf/_jobcontext.py

@@ -15,10 +15,10 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
+import shutil
+import sys
 from contextlib import suppress
 from multiprocessing.managers import SyncManager
-import sys
-import shutil
 
 from .pdfinfo import PdfInfo
 
@@ -77,8 +77,7 @@ class JobContextManager(SyncManager):
 
 def cleanup_working_files(work_folder, options):
     if options.keep_temporary_files:
-        print("Temporary working files saved at:\n{0}".format(work_folder),
-              file=sys.stderr)
+        print(f"Temporary working files saved at:\n{work_folder}", file=sys.stderr)
     else:
         with suppress(FileNotFoundError):
             shutil.rmtree(work_folder)

src/ocrmypdf/_unicodefun.py

@@ -33,12 +33,12 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
+import codecs
 import os
 import sys
-import codecs
 
 
-def verify_python3_env():
+def verify_python3_env():  # pragma: no cover
     """Ensures that the environment is good for unicode on Python 3."""
 
     # PEP 538 changes in Python 3.7 should make this wrangling unnecessary
@@ -47,6 +47,7 @@ def verify_python3_env():
 
     try:
         import locale
+
         fs_enc = codecs.lookup(locale.getpreferredencoding()).name
     except Exception:
         fs_enc = 'ascii'
@@ -56,8 +57,10 @@ def verify_python3_env():
     extra = ''
     if os.name == 'posix':
         import subprocess
-        rv = subprocess.Popen(['locale', '-a'], stdout=subprocess.PIPE,
-                              stderr=subprocess.PIPE).communicate()[0]
+
+        rv = subprocess.Popen(
+            ['locale', '-a'], stdout=subprocess.PIPE, stderr=subprocess.PIPE
+        ).communicate()[0]
         good_locales = set()
         has_c_utf8 = False
 
@@ -108,6 +111,8 @@ def verify_python3_env():
                 'is not supported'
             ) % bad_locale
 
-    raise RuntimeError('ocrmypdf will abort further execution because Python 3 '
-                       'was configured to use ASCII as encoding for the '
-                       'environment.' + extra)
+    raise RuntimeError(
+        'ocrmypdf will abort further execution because Python 3 '
+        'was configured to use ASCII as encoding for the '
+        'environment.' + extra
+    )

src/ocrmypdf/_weave.py

@@ -15,17 +15,21 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from pathlib import Path
 from itertools import groupby
+from pathlib import Path
+import os
 
 import pikepdf
 
-from .helpers import flatten_groups, page_number
 from .exec import tesseract
+from .helpers import flatten_groups, page_number
+
+
+MAX_OPEN_PAGE_PDFS = int(os.environ.get('_OCRMYPDF_MAX_OPEN_PAGE_PDFS', 100))
 
 
 def _update_page_resources(*, page, font, font_key, procset):
-    "Update this page's fonts with a reference to the Glyphless font"
+    """Update this page's fonts with a reference to the Glyphless font"""
 
     if '/Resources' not in page:
         page['/Resources'] = pikepdf.Dictionary({})
@@ -34,7 +38,7 @@ def _update_page_resources(*, page, font, font_key, procset):
         fonts = resources['/Font']
     except KeyError:
         fonts = pikepdf.Dictionary({})
-    if font_key not in fonts:
+    if font_key is not None and font_key not in fonts:
         fonts[font_key] = font
     resources['/Font'] = fonts
 
@@ -43,8 +47,54 @@ def _update_page_resources(*, page, font, font_key, procset):
     resources['/ProcSet'] = procset
 
 
+def strip_invisible_text(pdf, page, log):
+    stream = []
+    in_text_obj = False
+    render_mode = 0
+    text_objects = []
+
+    page.page_contents_coalesce()
+    for operands, operator in pikepdf.parse_content_stream(page, ''):
+        if not in_text_obj:
+            if operator == pikepdf.Operator('BT'):
+                in_text_obj = True
+                render_mode = 0
+                text_objects.append((operands, operator))
+            else:
+                stream.append((operands, operator))
+        else:
+            if operator == pikepdf.Operator('Tr'):
+                render_mode = operands[0]
+            text_objects.append((operands, operator))
+            if operator == pikepdf.Operator('ET'):
+                in_text_obj = False
+                if render_mode != 3:
+                    stream.extend(text_objects)
+                text_objects.clear()
+
+    def convert(op):
+        try:
+            return op.unparse()
+        except AttributeError:
+            return str(op).encode('ascii')
+
+    lines = []
+
+    for operands, operator in stream:
+        if operator == pikepdf.Operator('INLINE IMAGE'):
+            iim = operands[0]
+            line = iim.unparse()
+        else:
+            line = b' '.join(convert(op) for op in operands) + b' ' + operator.unparse()
+        lines.append(line)
+
+    content_stream = b'\n'.join(lines)
+    page.Contents = pikepdf.Stream(pdf, content_stream)
+
+
 def _weave_layers_graft(
-        *, pdf_base, page_num, text, font, font_key, procset, rotation, log):
+    *, pdf_base, page_num, text, font, font_key, procset, rotation, strip_old_text, log
+):
     """Insert the text layer from text page 0 on to pdf_base at page_num"""
 
     log.debug("Grafting")
@@ -62,7 +112,7 @@ def _weave_layers_graft(
         stream = bytearray(pdf_text_contents)
         pattern = b'/Im1 Do'
         idx = stream.find(pattern)
-        stream[idx:(idx + len(pattern))] = b' ' * len(pattern)
+        stream[idx : (idx + len(pattern))] = b' ' * len(pattern)
         pdf_text_contents = bytes(stream)
 
     base_page = pdf_base.pages.p(page_num)
@@ -71,12 +121,10 @@ def _weave_layers_graft(
     # content may have a rotation applied. Wrap the text stream with a rotation
     # so it will be oriented the same way as the rest of the page content.
     # (Previous versions OCRmyPDF rotated the content layer to match the text.)
-    mediabox = [float(pdf_text.pages[0].MediaBox[v])
-                for v in range(4)]
+    mediabox = [float(pdf_text.pages[0].MediaBox[v]) for v in range(4)]
     wt, ht = mediabox[2] - mediabox[0], mediabox[3] - mediabox[1]
 
-    mediabox = [float(base_page.MediaBox[v])
-                for v in range(4)]
+    mediabox = [float(base_page.MediaBox[v]) for v in range(4)]
     wp, hp = mediabox[2] - mediabox[0], mediabox[3] - mediabox[1]
 
     translate = pikepdf.PdfMatrix().translated(-wt / 2, -ht / 2)
@@ -101,14 +149,13 @@ def _weave_layers_graft(
     # for a size different between initial and text PDF, then untranslate
     ctm = translate @ rotate @ scale @ untranslate
 
-    pdf_text_contents = (
-        b'q %s cm\n' % ctm.encode() +
-        pdf_text_contents +
-        b'\nQ\n'
-    )
+    pdf_text_contents = b'q %s cm\n' % ctm.encode() + pdf_text_contents + b'\nQ\n'
 
     new_text_layer = pikepdf.Stream(pdf_base, pdf_text_contents)
 
+    if strip_old_text:
+        strip_invisible_text(pdf_base, base_page, log)
+
     base_page.page_contents_add(new_text_layer, prepend=True)
 
     _update_page_resources(
@@ -117,7 +164,7 @@ def _weave_layers_graft(
 
 
 def _find_font(text, pdf_base):
-    "Copy a font from the filename text into pdf_base"
+    """Copy a font from the filename text into pdf_base"""
 
     font, font_key = None, None
     possible_font_names = ('/f-0-0', '/F1')
@@ -134,9 +181,55 @@ def _find_font(text, pdf_base):
             break
     if pdf_text_font:
         font = pdf_base.copy_foreign(pdf_text_font)
+    if font_key is None:
+        print('font_key is None')
     return font, font_key
 
 
+def _traverse_toc(pdf_base, visitor_fn, log):
+    """
+    Walk the table of contents, calling visitor_fn() at each node
+
+    The /Outlines data structure is a messy data structure, but rather than
+    navigating hierarchically we just track unique nodes.  Enqueue nodes when
+    we find them, and never visit them again.  set() is awesome.  We look for
+    the two types of object in the table of contents that can be page bookmarks
+    and update the page entry.
+
+    """
+
+    visited = set()
+    queue = set()
+    link_keys = ('/Parent', '/First', '/Last', '/Prev', '/Next')
+
+    if not '/Outlines' in pdf_base.root:
+        return
+
+    queue.add(pdf_base.root.Outlines.objgen)
+    while queue:
+        objgen = queue.pop()
+        visited.add(objgen)
+        node = pdf_base.get_object(objgen)
+        log.debug('fix toc: exploring outline entries at %r', objgen)
+
+        # Enumerate other nodes we could visit from here
+        for key in link_keys:
+            if key not in node:
+                continue
+            item = node[key]
+            if not item.is_indirect:
+                # Direct references are not allowed here, but it's not clear
+                # what we should do if we find any. Removing them is an option:
+                # node[key] = pdf_base.make_indirect(None)
+                continue
+            objgen = item.objgen
+            if objgen not in visited:
+                queue.add(objgen)
+
+        if visitor_fn:
+            visitor_fn(pdf_base, node, log)
+
+
 def _fix_toc(pdf_base, pageref_remap, log):
     """Repair the table of contents
 
@@ -146,64 +239,47 @@ def _fix_toc(pdf_base, pageref_remap, log):
     pageref_remap, a mapping that describes the new objgen number given an old
     one.  (objgen is a tuple, and the gen is almost always zero.)
 
-    The /Outlines data structure is a messy data structure, but rather than
-    navigating hierarchically we just track unique nodes.  Enqueue nodes when
-    we find them, and never visit them again.  set() is awesome.  We look for
-    the two types of object in the table of contents that can be page bookmarks
-    and update the page entry.
-
     It may ultimately be better to find a way to rebuild a page in place.
 
     """
 
-    visited = set()
-    queue = set()
-    link_keys = ('/Parent', '/First', '/Last', '/Prev', '/Next')
-
-    if not '/Outlines' in pdf_base.root:
-        return
     if not pageref_remap:
         return
 
     def remap_dest(dest_node):
-        if not isinstance(dest_node, pikepdf.Array):
-            return
-        pageref = dest_node[0]
-        if pageref['/Type'] == '/Page' and \
-                pageref.objgen in pageref_remap:
-            new_objgen = pageref_remap[pageref.objgen]
-            dest_node[0] = pdf_base.get_object(new_objgen)
+        """
+        Inner helper function: change the objgen for any page from the old we
+        invalidated to its new one.
+        """
+        try:
+            pageref = dest_node[0]
+            if pageref['/Type'] == '/Page' and pageref.objgen in pageref_remap:
+                new_objgen = pageref_remap[pageref.objgen]
+                dest_node[0] = pdf_base.get_object(new_objgen)
+        except (IndexError, TypeError) as e:
+            log.warning("This file may contain invalid table of contents entries")
+            log.debug(e)
 
-    queue.add(pdf_base.root.Outlines.objgen)
-    while queue:
-        objgen = queue.pop()
-        visited.add(objgen)
-        node = pdf_base.get_object(objgen)
-        log.debug('fix toc: visiting %r', objgen)
-
-        # Enumerate other nodes we could visit from here
-        for key in link_keys:
-            if key not in node:
-                continue
-            item = node[key]
-            if not item.is_indirect:
-                continue
-            objgen = item.objgen
-            if objgen not in visited:
-                queue.add(objgen)
+    def visit_remap_dest(pdf_base, node, log):
+        """
+        Visitor function to fix ToC entries
 
+        Test for the two types of references to pages that can occur in ToCs.
+        Both types have the same final format (an indirect reference to the
+        target page).
+        """
         if '/Dest' in node:
+            # /Dest reference to another page (old method)
             remap_dest(node['/Dest'])
         elif '/A' in node:
+            # /A (action) command set to "GoTo" (newer method)
             if '/S' in node['/A'] and node['/A']['/S'] == '/GoTo':
                 remap_dest(node['/A']['/D'])
 
+    _traverse_toc(pdf_base, visit_remap_dest, log)
 
-def weave_layers(
-        infiles,
-        output_file,
-        log,
-        context):
+
+def weave_layers(infiles, output_file, log, context):
     """Apply text layer and/or image layer changes to baseline file
 
     This is where the magic happens. infiles will be the main PDF to modify,
@@ -234,6 +310,7 @@ def weave_layers(
             return page_number(key)
         except ValueError:
             return -1
+
     flat_inputs = sorted(flatten_groups(infiles), key=input_sorter)
     groups = groupby(flat_inputs, key=input_sorter)
 
@@ -247,8 +324,15 @@ def weave_layers(
     pdfinfo = context.get_pdfinfo()
     pagerefs = {}
 
+    # Walk the table of contents first, to trigger pikepdf/qpdf to resolve all
+    # page references in the table of contents. Some PDF generators put invalid
+    # references in the ToC, so we want to resolve them to null before we
+    # create any references, or the ToC will be corrupted
+    _traverse_toc(pdf_base, None, log)
+
     procset = pdf_base.make_indirect(
-        pikepdf.Object.parse(b'[ /PDF /Text /ImageB /ImageC /ImageI ]'))
+        pikepdf.Object.parse(b'[ /PDF /Text /ImageB /ImageC /ImageI ]')
+    )
 
     # Iterate rest
     for page_num, layers in groups:
@@ -256,12 +340,8 @@ def weave_layers(
         log.debug(page_num)
         log.debug(layers)
 
-        text = next(
-            (ii for ii in layers if ii.endswith('.text.pdf')), None
-        )
-        image = next(
-            (ii for ii in layers if ii.endswith('.image-layer.pdf')), None
-        )
+        text = next((ii for ii in layers if ii.endswith('.text.pdf')), None)
+        image = next((ii for ii in layers if ii.endswith('.image-layer.pdf')), None)
 
         if text and not font:
             font, font_key = _find_font(text, pdf_base)
@@ -293,24 +373,32 @@ def weave_layers(
             content_rotation = autorotate_correction
         text_rotation = autorotate_correction
         text_misaligned = (text_rotation - content_rotation) % 360
-        log.debug('%r', [
-            text_rotation, autorotate_correction, text_misaligned,
-            content_rotation]
+        log.debug(
+            '%r',
+            [text_rotation, autorotate_correction, text_misaligned, content_rotation],
         )
 
         if text and font:
             # Graft the text layer onto this page, whether new or old
+            strip_old = context.get_options().redo_ocr
             _weave_layers_graft(
-                pdf_base=pdf_base, page_num=page_num, text=text, font=font,
-                font_key=font_key, rotation=text_misaligned, procset=procset,
-                log=log
+                pdf_base=pdf_base,
+                page_num=page_num,
+                text=text,
+                font=font,
+                font_key=font_key,
+                rotation=text_misaligned,
+                procset=procset,
+                strip_old_text=strip_old,
+                log=log,
             )
 
         # Correct the rotation if applicable
-        pdf_base.pages[page_num - 1].Rotate = \
-            (content_rotation - autorotate_correction) % 360
+        pdf_base.pages[page_num - 1].Rotate = (
+            content_rotation - autorotate_correction
+        ) % 360
 
-        if len(keep_open) > 100:
+        if len(keep_open) > MAX_OPEN_PAGE_PDFS:
             # qpdf limitations require us to keep files open when we intend
             # to copy content from them before saving. However, we want to keep
             # a lid on file handles and memory usage, so for big files we're
@@ -318,15 +406,16 @@ def weave_layers(
             # even if page 1 doesn't use it, so we have a way to get it back.
             page0 = pdf_base.pages[0]
             _update_page_resources(
-                page=page0, font=font, font_key=font_key, procset=procset)
-            interim = output_file + '_working{}.pdf'.format(page_num)
+                page=page0, font=font, font_key=font_key, procset=procset
+            )
+            interim = output_file + f'_working{page_num}.pdf'
             pdf_base.save(interim)
             del pdf_base
             keep_open = []
 
             pdf_base = pikepdf.open(interim)
             procset = pdf_base.pages[0].Resources.ProcSet
-            font = pdf_base.pages[0].Resources.Font.get(font_key)
+            font, font_key = None, None  # Reacquire this information
 
     _fix_toc(pdf_base, pagerefs, log)
     pdf_base.save(output_file)

src/ocrmypdf/exceptions.py

@@ -17,6 +17,8 @@
 
 
 from enum import IntEnum
+from textwrap import dedent
+
 
 class ExitCode(IntEnum):
     ok = 0
@@ -36,6 +38,13 @@ class ExitCode(IntEnum):
 
 class ExitCodeException(Exception):
     exit_code = ExitCode.other_error
+    message = ""
+
+    def __str__(self):
+        super_msg = super().__str__()  # Don't do str(super())
+        if self.message:
+            return self.message.format(super_msg)
+        return super_msg
 
 
 class BadArgsError(ExitCodeException):
@@ -44,6 +53,17 @@ class BadArgsError(ExitCodeException):
 
 class PdfMergeFailedError(ExitCodeException):
     exit_code = ExitCode.input_file
+    message = dedent(
+        '''\
+        Failed to merge PDF image layer with OCR layer
+
+        Usually this happens because the input PDF file is malformed and
+        ocrmypdf cannot automatically correct the problem on its own.
+
+        Try using
+            ocrmypdf --pdf-renderer sandwich  [..other args..]
+        '''
+    )
 
 
 class MissingDependencyError(ExitCodeException):
@@ -76,7 +96,20 @@ class SubprocessOutputError(ExitCodeException):
 
 class EncryptedPdfError(ExitCodeException):
     exit_code = ExitCode.encrypted_pdf
+    message = dedent(
+        '''\
+        Input PDF is encrypted. The encryption must be removed to
+        perform OCR.
+
+        For information about this PDF's security use
+            qpdf --show-encryption infilename
+
+        You can remove the encryption using
+            qpdf --decrypt [--password=[password]] infilename
+        '''
+    )
 
 
 class TesseractConfigError(ExitCodeException):
     exit_code = ExitCode.invalid_config
+    message = "Error occurred while parsing a Tesseract configuration file"

src/ocrmypdf/exec/__init__.py

@@ -24,37 +24,37 @@ from subprocess import run, STDOUT, PIPE, CalledProcessError
 from ..exceptions import MissingDependencyError
 
 
-
-def get_version(program, *,
-        version_arg='--version', regex=r'(\d+(\.\d+)*)'):
+def get_version(program, *, version_arg='--version', regex=r'(\d+(\.\d+)*)'):
     "Get the version of the specified program"
-    args_prog = [
-        program,
-        version_arg
-    ]
+    args_prog = [program, version_arg]
     try:
         proc = run(
-            args_prog, close_fds=True, universal_newlines=True,
-            stdout=PIPE, stderr=STDOUT, check=True)
+            args_prog,
+            close_fds=True,
+            universal_newlines=True,
+            stdout=PIPE,
+            stderr=STDOUT,
+            check=True,
+        )
         output = proc.stdout
     except FileNotFoundError as e:
         raise MissingDependencyError(
-            "Could not find program '{}' on the PATH".format(
-                program)) from e
+            f"Could not find program '{program}' on the PATH"
+        ) from e
     except CalledProcessError as e:
         if e.returncode < 0:
             raise MissingDependencyError(
-                "Ran program '{}' but it exited with an error:\n{}".format(
-                    program, e.output)) from e
+                f"Ran program '{program}' but it exited with an error:\n{e.output}"
+            ) from e
         raise MissingDependencyError(
-            "Could not find program '{}' on the PATH".format(
-                program)) from e
+            f"Could not find program '{program}' on the PATH"
+        ) from e
     try:
         version = re.match(regex, output.strip()).group(1)
     except AttributeError as e:
         raise MissingDependencyError(
-            ("The program '{}' did not report its version. "
-            "Message was:\n{}").format(program, output)
+            f"The program '{program}' did not report its version. "
+            f"Message was:\n{output}"
         )
 
     return version

src/ocrmypdf/exec/ghostscript.py

@@ -15,15 +15,17 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from tempfile import NamedTemporaryFile
-from subprocess import run, PIPE, STDOUT
-from shutil import copy
-from functools import lru_cache
 import re
+from functools import lru_cache
+from os import fspath
+from shutil import copy
+from subprocess import PIPE, STDOUT, run
+from tempfile import NamedTemporaryFile
+
 from PIL import Image
+
 from . import get_version
 from ..exceptions import SubprocessOutputError
-from ..helpers import fspath
 
 
 @lru_cache(maxsize=1)
@@ -32,15 +34,20 @@ def version():
 
 
 def jpeg_passthrough_available():
-    """
-    Ghostscript 9.23 introduced JPEG passthrough but it seems to corrupt the
-    last two bytes of certain images, for now we disable it for 9.23 and
-    do not mention it for < 9.23.
+    """Returns True if the installed version of Ghostscript supports JPEG passthru
 
+    Prior to 9.23, Ghostscript decode and re-encoded JPEGs internally. In 9.23
+    it gained the ability to keep JPEGs unmodified. However, the 9.23
+    implementation was buggy and would deletes the last two bytes of images in
+    some cases, as reported here.
     https://bugs.ghostscript.com/show_bug.cgi?id=699216
 
+    The issue was fixed for 9.24, hence that is the first version we consider
+    the feature available. (However, we don't use 9.24 at all, so the first
+    version that allows JPEG passthrough is 9.25.
+
     """
-    return False
+    return version() >= '9.24'
 
 
 def _gs_error_reported(stream):
@@ -48,8 +55,7 @@ def _gs_error_reported(stream):
 
 
 def extract_text(input_file, pageno=1):
-    """
-    Use the txtwrite device to get text layout information out
+    """Use the txtwrite device to get text layout information out
 
     For details on options of -dTextFormat see
     https://www.ghostscript.com/doc/current/VectorDevices.htm#TXT
@@ -60,39 +66,52 @@ def extract_text(input_file, pageno=1):
     <span bbox="left top right bottom" font="..." size="...">
     <char bbox="...." c="X"/>
 
+    :param pageno: number of page to extract, or all pages if None
     :return: XML-ish text representation in bytes
-
     """
 
-    args_gs = [
-        'gs',
-        '-dQUIET',
-        '-dSAFER',
-        '-dBATCH',
-        '-dNOPAUSE',
-        '-sDEVICE=txtwrite',
-        '-dTextFormat=0',
-        '-dFirstPage=%i' % pageno,
-        '-dLastPage=%i' % pageno,
-        '-o', '-',
-        input_file
-    ]
+    if pageno is not None:
+        pages = ['-dFirstPage=%i' % pageno, '-dLastPage=%i' % pageno]
+    else:
+        pages = []
+
+    args_gs = (
+        [
+            'gs',
+            '-dQUIET',
+            '-dSAFER',
+            '-dBATCH',
+            '-dNOPAUSE',
+            '-sDEVICE=txtwrite',
+            '-dTextFormat=0',
+        ]
+        + pages
+        + ['-o', '-', fspath(input_file)]
+    )
 
     p = run(args_gs, stdout=PIPE, stderr=PIPE)
     if p.returncode != 0:
         raise SubprocessOutputError(
-            'Ghostscript text extraction failed\n%s\n%s\n%s' % (
-                input_file, p.stdout.decode(), p.stderr.decode()
-            )
+            'Ghostscript text extraction failed\n%s\n%s\n%s'
+            % (input_file, p.stdout.decode(), p.stderr.decode())
         )
 
     return p.stdout
 
 
-def rasterize_pdf(input_file, output_file, xres, yres, raster_device, log,
-                  pageno=1, page_dpi=None, rotation=None):
-    """
-    Rasterize one page of a PDF at resolution (xres, yres) in canvas units.
+def rasterize_pdf(
+    input_file,
+    output_file,
+    xres,
+    yres,
+    raster_device,
+    log,
+    pageno=1,
+    page_dpi=None,
+    rotation=None,
+    filter_vector=False,
+):
+    """Rasterize one page of a PDF at resolution (xres, yres) in canvas units.
 
     The image is sized to match the integer pixels dimensions implied by
     (xres, yres) even if those numbers are noninteger. The image's DPI will
@@ -106,6 +125,8 @@ def rasterize_pdf(input_file, output_file, xres, yres, raster_device, log,
     :param log:
     :param pageno: page number to rasterize (beginning at page 1)
     :param page_dpi: resolution tuple (x, y) overriding output image DPI
+    :param rotation: 0, 90, 180, 270: clockwise angle to rotate page
+    :param filter_vector: if True, remove vector graphics objects
     :return:
     """
     res = xres, yres
@@ -114,25 +135,30 @@ def rasterize_pdf(input_file, output_file, xres, yres, raster_device, log,
         page_dpi = res
 
     with NamedTemporaryFile(delete=True) as tmp:
-        args_gs = [
-            'gs',
-            '-dQUIET',
-            '-dSAFER',
-            '-dBATCH',
-            '-dNOPAUSE',
-            '-sDEVICE=%s' % raster_device,
-            '-dFirstPage=%i' % pageno,
-            '-dLastPage=%i' % pageno,
-            '-r{0}x{1}'.format(str(int_res[0]), str(int_res[1])),
-            '-o', tmp.name,
-            '-dAutoRotatePages=/None',  # Probably has no effect on raster
-            '-f',
-            fspath(input_file)
-        ]
+        args_gs = (
+            [
+                'gs',
+                '-dQUIET',
+                '-dSAFER',
+                '-dBATCH',
+                '-dNOPAUSE',
+                f'-sDEVICE={raster_device}',
+                f'-dFirstPage={pageno}',
+                f'-dLastPage={pageno}',
+                f'-r{str(int_res[0])}x{str(int_res[1])}',
+            ]
+            + (['-dFILTERVECTOR'] if filter_vector else [])
+            + [
+                '-o',
+                tmp.name,
+                '-dAutoRotatePages=/None',  # Probably has no effect on raster
+                '-f',
+                fspath(input_file),
+            ]
+        )
 
         log.debug(args_gs)
-        p = run(args_gs, stdout=PIPE, stderr=STDOUT,
-                universal_newlines=True)
+        p = run(args_gs, stdout=PIPE, stderr=STDOUT, universal_newlines=True)
         if _gs_error_reported(p.stdout):
             log.error(p.stdout)
         else:
@@ -149,12 +175,14 @@ def rasterize_pdf(input_file, output_file, xres, yres, raster_device, log,
 
         tmp.seek(0)
         with Image.open(tmp) as im:
-            expected_size = round(im.size[0] / int_res[0] * res[0]), \
-                            round(im.size[1] / int_res[1] * res[1])
+            expected_size = (
+                round(im.size[0] / int_res[0] * res[0]),
+                round(im.size[1] / int_res[1] * res[1]),
+            )
             if expected_size != im.size or page_dpi != (xres, yres):
                 log.debug(
-                    "Ghostscript: resize output image {} -> {}".format(
-                        im.size, expected_size))
+                    f"Ghostscript: resize output image {im.size} -> {expected_size}"
+                )
                 im = im.resize(expected_size)
 
             if rotation is not None:
@@ -172,8 +200,32 @@ def rasterize_pdf(input_file, output_file, xres, yres, raster_device, log,
             im.save(fspath(output_file), dpi=page_dpi)
 
 
-def generate_pdfa(pdf_pages, output_file, compression, log,
-                  threads=1, pdf_version='1.5', pdfa_part='2'):
+def generate_pdfa(
+    pdf_pages,
+    output_file,
+    compression,
+    log,
+    threads=1,
+    pdf_version='1.5',
+    pdfa_part='2',
+):
+    """Generate a PDF/A.
+
+    The pdf_pages, a list files, will be merged into output_file. One or more
+    PDF files may be merged. One of the files in this list must be a pdfmark
+    file that provides Ghostscript with details on how to perform the PDF/A
+    conversion. By default with we pick PDF/A-2b, but this works for 1 or 3.
+
+    compression can be 'jpeg', 'lossless', or an empty string. In 'jpeg',
+    Ghostscript is instructed to convert color and grayscale images to DCT
+    (JPEG encoding). In 'lossless' Ghostscript is told to convert images to
+    Flate (lossless/PNG). If the parameter is omitted Ghostscript is left to
+    make its own decisions about how to encode images; it appears to use a
+    heuristic to decide how to encode images. As of Ghostscript 9.25, we
+    support passthrough JPEG which allows Ghostscript to avoid transcoding
+    images entirely. (The feature was added in 9.23 but broken, and the 9.24
+    release of Ghostscript had regressions, so we don't support it until 9.25.)
+    """
     compression_args = []
     if compression == 'jpeg':
         compression_args = [
@@ -207,27 +259,32 @@ def generate_pdfa(pdf_pages, output_file, compression, log,
         compression_args.append('-dPassThroughJPEGImages=false')
 
     with NamedTemporaryFile(delete=True) as gs_pdf:
-        args_gs = [
-            "gs",
-            "-dQUIET",
-            "-dBATCH",
-            "-dNOPAUSE",
-            "-dCompatibilityLevel=" + str(pdf_version),
-            "-dNumRenderingThreads=" + str(threads),
-            "-sDEVICE=pdfwrite",
-            "-dAutoRotatePages=/None",
-            "-sColorConversionStrategy=" + strategy,
-            "-sProcessColorModel=DeviceRGB"
-        ] + compression_args + [
-            "-dJPEGQ=95",
-            "-dPDFA=" + pdfa_part,
-            "-dPDFACompatibilityPolicy=1",
-            "-sOutputFile=" + gs_pdf.name,
-        ]
+        # nb no need to specify ProcessColorModel when ColorConversionStrategy
+        # is set; see:
+        # https://bugs.ghostscript.com/show_bug.cgi?id=699392
+        args_gs = (
+            [
+                "gs",
+                "-dQUIET",
+                "-dBATCH",
+                "-dNOPAUSE",
+                "-dCompatibilityLevel=" + str(pdf_version),
+                "-dNumRenderingThreads=" + str(threads),
+                "-sDEVICE=pdfwrite",
+                "-dAutoRotatePages=/None",
+                "-sColorConversionStrategy=" + strategy,
+            ]
+            + compression_args
+            + [
+                "-dJPEGQ=95",
+                "-dPDFA=" + pdfa_part,
+                "-dPDFACompatibilityPolicy=1",
+                "-sOutputFile=" + gs_pdf.name,
+            ]
+        )
         args_gs.extend(fspath(s) for s in pdf_pages)  # Stringify Path objs
         log.debug(args_gs)
-        p = run(args_gs, stdout=PIPE, stderr=STDOUT,
-                universal_newlines=True)
+        p = run(args_gs, stdout=PIPE, stderr=STDOUT, universal_newlines=True)
 
         if _gs_error_reported(p.stdout):
             log.error(p.stdout)
@@ -238,7 +295,7 @@ def generate_pdfa(pdf_pages, output_file, compression, log,
             log.debug(
                 "Ghostscript had to remove PDF 'overprinting' from the "
                 "input file to complete PDF/A conversion. "
-                )
+            )
         else:
             log.debug(p.stdout)
 

src/ocrmypdf/exec/jbig2enc.py

@@ -15,14 +15,11 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from subprocess import CalledProcessError, run, PIPE
 from functools import lru_cache
-import sys
-import os
-import shutil
+from subprocess import PIPE, run
 
 from . import get_version
-from ..exceptions import ExitCode, MissingDependencyError
+from ..exceptions import MissingDependencyError
 
 
 @lru_cache(maxsize=1)
@@ -30,7 +27,6 @@ def version():
     return get_version('jbig2', regex=r'jbig2enc (\d+(\.\d+)*).*')
 
 
-@lru_cache(maxsize=1)
 def available():
     try:
         version()
@@ -44,10 +40,20 @@ def convert_group(*, cwd, infiles, out_prefix):
         'jbig2',
         '-b',
         out_prefix,
-        '-s',
+        '-s',  # symbol mode (lossy)
+        # '-r', # refinement mode (lossless symbol mode, currently disabled in
+        # jbig2)
         '-p',
     ]
     args.extend(infiles)
     proc = run(args, cwd=cwd, stdout=PIPE, stderr=PIPE)
     proc.check_returncode()
-    return proc
+    return proc
+
+
+def convert_single(*, cwd, infile, outfile):
+    args = ['jbig2', '-p', infile]
+    with open(outfile, 'wb') as fstdout:
+        proc = run(args, cwd=cwd, stdout=fstdout, stderr=PIPE)
+    proc.check_returncode()
+    return proc

src/ocrmypdf/exec/pngquant.py

@@ -15,15 +15,11 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from subprocess import CalledProcessError, run
-from tempfile import TemporaryFile
 from functools import lru_cache
-import sys
-import os
-import shutil
+from subprocess import run
 
 from . import get_version
-from ..exceptions import ExitCode
+from ..exceptions import MissingDependencyError
 
 
 @lru_cache(maxsize=1)
@@ -31,15 +27,25 @@ def version():
     return get_version('pngquant', regex=r'(\d+(\.\d+)*).*')
 
 
+def available():
+    try:
+        version()
+    except MissingDependencyError:
+        return False
+    return True
+
+
 def quantize(input_file, output_file, quality_min, quality_max):
     args = [
         'pngquant',
         '--force',
         '--skip-if-larger',
-        '--output', output_file,
-        '--quality', '{}-{}'.format(quality_min, quality_max),
+        '--output',
+        output_file,
+        '--quality',
+        f'{quality_min}-{quality_max}',
         '--',
-        input_file
+        input_file,
     ]
     proc = run(args)
-    proc.check_returncode()
+    proc.check_returncode()

src/ocrmypdf/exec/qpdf.py

@@ -15,12 +15,11 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from subprocess import CalledProcessError, STDOUT, PIPE, run
 from functools import lru_cache
+from os import fspath
+from subprocess import PIPE, STDOUT, CalledProcessError, run
 
-from ..exceptions import InputFileError, SubprocessOutputError, \
-    EncryptedPdfError
-from . import  get_version
+from . import get_version
 
 
 @lru_cache(maxsize=1)
@@ -29,22 +28,16 @@ def version():
 
 
 def check(input_file, log=None):
-    args_qpdf = [
-        'qpdf',
-        '--check',
-        input_file
-    ]
+    args_qpdf = ['qpdf', '--check', fspath(input_file)]
 
     if log is None:
         import logging as log
 
     try:
-        run(args_qpdf, stderr=STDOUT, stdout=PIPE, universal_newlines=True,
-            check=True)
+        run(args_qpdf, stderr=STDOUT, stdout=PIPE, universal_newlines=True, check=True)
     except CalledProcessError as e:
         if e.returncode == 2:
-            log.error("%s: not a valid PDF, and could not repair it.",
-                input_file)
+            log.error("%s: not a valid PDF, and could not repair it.", input_file)
             log.error("Details:")
             log.error(e.output)
         elif e.returncode == 3:

src/ocrmypdf/exec/tesseract.py

@@ -15,22 +15,28 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-import sys
 import os
 import shutil
-from functools import lru_cache
+import sys
 from collections import namedtuple
-from textwrap import dedent
-from subprocess import CalledProcessError, TimeoutExpired, check_output, STDOUT
 from contextlib import suppress
+from functools import lru_cache
+from os import fspath
+from subprocess import (
+    PIPE,
+    STDOUT,
+    CalledProcessError,
+    TimeoutExpired,
+    check_output,
+    run,
+)
+from textwrap import dedent
 
+from . import get_version
 from ..exceptions import MissingDependencyError, TesseractConfigError
 from ..helpers import page_number
-from . import get_version
 
-OrientationConfidence = namedtuple(
-    'OrientationConfidence',
-    ('angle', 'confidence'))
+OrientationConfidence = namedtuple('OrientationConfidence', ('angle', 'confidence'))
 
 HOCR_TEMPLATE = """<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
@@ -39,8 +45,8 @@ HOCR_TEMPLATE = """<?xml version="1.0" encoding="UTF-8"?>
  <head>
   <title></title>
 <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
-  <meta name='ocr-system' content='tesseract 3.05.00' />
-  <meta name='ocr-capabilities' content='ocr_page ocr_carea ocr_par ocr_line ocrx_word'/>
+  <meta name='ocr-system' content='tesseract 4.0.0' />
+  <meta name='ocr-capabilities' content='ocr_page ocr_carea ocr_par ocr_line ocrx_word ocrp_wconf'/>
 </head>
 <body>
   <div class='ocr_page' id='page_1' title='image "_blank.png"; bbox 0 0 {0} {1}; ppageno 0'>
@@ -64,56 +70,52 @@ def v4():
 def has_textonly_pdf():
     """Does Tesseract have textonly_pdf capability?
 
-    Available in 3.05.01, and v4.00.00alpha since January 2017. Best to
+    Available in v4.00.00alpha since January 2017. Best to
     parse the parameter list
     """
-    args_tess = [
-        'tesseract',
-        '--print-parameters',
-        'pdf'
-    ]
+    args_tess = ['tesseract', '--print-parameters', 'pdf']
     params = ''
     try:
-        params = check_output(
-                args_tess, universal_newlines=True, stderr=STDOUT)
+        params = check_output(args_tess, universal_newlines=True, stderr=STDOUT)
     except CalledProcessError as e:
-        print("Could not --print-parameters from tesseract",
-              file=sys.stderr)
+        print("Could not --print-parameters from tesseract", file=sys.stderr)
         raise MissingDependencyError from e
     if 'textonly_pdf' in params:
         return True
     return False
 
 
-def psm():
-    "If Tesseract 4.0, use argument --psm instead of -psm"
-    return '--psm' if v4() else '-psm'
-
-
 @lru_cache(maxsize=1)
 def languages():
-    args_tess = [
-        'tesseract',
-        '--list-langs'
-    ]
-    try:
-        langs = check_output(
-                args_tess, universal_newlines=True, stderr=STDOUT)
-    except CalledProcessError as e:
-        msg = dedent("""Tesseract failed to report available languages.
+    def lang_error(output):
+        msg = dedent(
+            """Tesseract failed to report available languages.
         Output from Tesseract:
         -----------
-        """)
-        msg += e.output
+        """
+        )
+        msg += output
         print(msg, file=sys.stderr)
+
+    args_tess = ['tesseract', '--list-langs']
+    try:
+        proc = run(
+            args_tess, universal_newlines=True, stdout=PIPE, stderr=STDOUT, check=True
+        )
+        output = proc.stdout
+    except CalledProcessError as e:
+        lang_error(e.output)
         raise MissingDependencyError from e
-    return set(lang.strip() for lang in langs.splitlines()[1:])
+
+    header, *rest = output.splitlines()
+    if not header.startswith('List of available languages'):
+        lang_error(output)
+        raise MissingDependencyError
+    return set(lang.strip() for lang in rest)
 
 
 def tess_base_args(langs, engine_mode):
-    args = [
-        'tesseract',
-    ]
+    args = ['tesseract']
     if langs:
         args.extend(['-l', '+'.join(langs)])
     if engine_mode is not None and v4():
@@ -123,20 +125,22 @@ def tess_base_args(langs, engine_mode):
 
 def get_orientation(input_file, engine_mode, timeout: float, log):
     args_tesseract = tess_base_args(['osd'], engine_mode) + [
-        psm(), '0',
-        input_file,
-        'stdout'
+        '--psm',
+        '0',
+        fspath(input_file),
+        'stdout',
     ]
 
     try:
-        stdout = check_output(
-            args_tesseract, stderr=STDOUT, timeout=timeout)
+        stdout = check_output(args_tesseract, stderr=STDOUT, timeout=timeout)
     except TimeoutExpired:
         return OrientationConfidence(angle=0, confidence=0.0)
     except CalledProcessError as e:
         tesseract_log_output(log, e.output, input_file)
-        if (b'Too few characters. Skipping this page' in e.output or
-                b'Image too large' in e.output):
+        if (
+            b'Too few characters. Skipping this page' in e.output
+            or b'Image too large' in e.output
+        ):
             return OrientationConfidence(0, 0)
         raise e from e
     else:
@@ -148,32 +152,24 @@ def get_orientation(input_file, engine_mode, timeout: float, log):
                 osd[parts[0].strip()] = parts[1].strip()
 
         angle = int(osd.get('Orientation in degrees', 0))
-        if 'Orientation' in osd:
-            # Tesseract < 3.04.01
-            # reports "Orientation in degrees" as a counterclockwise angle
-            # We keep it clockwise
-            assert 'Rotate' not in osd
-            angle = -angle % 360
-        else:
-            # Tesseract >= 3.04.01
-            # reports "Orientation in degrees" as a clockwise angle
-            assert 'Rotate' in osd
-
         oc = OrientationConfidence(
-            angle=angle,
-            confidence=float(osd.get('Orientation confidence', 0)))
+            angle=angle, confidence=float(osd.get('Orientation confidence', 0))
+        )
         return oc
 
 
 def tesseract_log_output(log, stdout, input_file):
-    prefix = "{0:4d}: [tesseract] ".format(page_number(input_file))
+    prefix = f"{(page_number(input_file)):4d}: [tesseract] "
 
     try:
         text = stdout.decode()
     except UnicodeDecodeError:
-        log.error(prefix + "command line output was not utf-8. " +
-            "This usually means Tesseract's language packs do not match "
-            "the installed version of Tesseract.")
+        log.error(
+            prefix
+            + "command line output was not utf-8. "
+            + "This usually means Tesseract's language packs do not match "
+            "the installed version of Tesseract."
+        )
         text = stdout.decode('utf-8', 'backslashreplace')
 
     lines = text.splitlines()
@@ -190,6 +186,10 @@ def tesseract_log_output(log, stdout, input_file):
             pass  # Appears to be spurious/problem with nonwhite borders
         elif 'Error in boxClipToRectangle' in line:
             pass  # Always appears with pixScanForForeground message
+        elif 'parameter not found: ' in line.lower():
+            log.error(prefix + line.strip())
+            problem = line.split('found: ')[1]
+            raise TesseractConfigError(problem)
         elif 'error' in line.lower() or 'exception' in line.lower():
             log.error(prefix + line.strip())
         elif 'warning' in line.lower():
@@ -200,8 +200,10 @@ def tesseract_log_output(log, stdout, input_file):
             log.info(prefix + line.strip())
 
 
-def page_timedout(log, input_file):
-    prefix = "{0:4d}: [tesseract] ".format(page_number(input_file))
+def page_timedout(log, input_file, timeout):
+    if timeout == 0:
+        return
+    prefix = f"{(page_number(input_file)):4d}: [tesseract] "
     log.warning(prefix + " took too long to OCR - skipping")
 
 
@@ -219,10 +221,18 @@ def _generate_null_hocr(output_hocr, output_sidecar, image):
         f.write('[skipped page]')
 
 
-def generate_hocr(input_file, output_files, language: list, engine_mode,
-                  tessconfig: list,
-                  timeout: float, pagesegmode: int, user_words, user_patterns,
-                  log):
+def generate_hocr(
+    input_file,
+    output_files,
+    language: list,
+    engine_mode,
+    tessconfig: list,
+    timeout: float,
+    pagesegmode: int,
+    user_words,
+    user_patterns,
+    log,
+):
 
     output_hocr = next(o for o in output_files if o.endswith('.hocr'))
     output_sidecar = next(o for o in output_files if o.endswith('.txt'))
@@ -231,7 +241,7 @@ def generate_hocr(input_file, output_files, language: list, engine_mode,
     args_tesseract = tess_base_args(language, engine_mode)
 
     if pagesegmode is not None:
-        args_tesseract.extend([psm(), str(pagesegmode)])
+        args_tesseract.extend(['--psm', str(pagesegmode)])
 
     if user_words:
         args_tesseract.extend(['--user-words', user_words])
@@ -241,30 +251,18 @@ def generate_hocr(input_file, output_files, language: list, engine_mode,
 
     # Reminder: test suite tesseract spoofers will break after any changes
     # to the number of order parameters here
-    # Tesseract 3.04 requires the order here to be "hocr txt" and will fail
-    # on "txt hocr"
-
-    args_tesseract.extend([
-        input_file,
-        prefix,
-        'hocr',
-        'txt'
-    ] + tessconfig)
+    args_tesseract.extend([input_file, prefix, 'hocr', 'txt'] + tessconfig)
     try:
         log.debug(args_tesseract)
-        stdout = check_output(
-            args_tesseract, stderr=STDOUT,
-            timeout=timeout)
+        stdout = check_output(args_tesseract, stderr=STDOUT, timeout=timeout)
     except TimeoutExpired:
         # Generate a HOCR file with no recognized text if tesseract times out
         # Temporary workaround to hocrTransform not being able to function if
         # it does not have a valid hOCR file.
-        page_timedout(log, input_file)
+        page_timedout(log, input_file, timeout)
         _generate_null_hocr(output_hocr, output_sidecar, input_file)
     except CalledProcessError as e:
         tesseract_log_output(log, e.output, input_file)
-        if b'read_params_file: parameter not found' in e.output:
-            raise TesseractConfigError() from e
         if b'Image too large' in e.output:
             _generate_null_hocr(output_hocr, output_sidecar, input_file)
             return
@@ -294,10 +292,22 @@ def use_skip_page(text_only, skip_pdf, output_pdf, output_text):
         out.write(b'')
 
 
-def generate_pdf(*, input_image, skip_pdf=None, output_pdf, output_text,
-                 language: list, engine_mode, text_only: bool,
-                 tessconfig: list, timeout: float, pagesegmode: int,
-                 user_words, user_patterns, log):
+def generate_pdf(
+    *,
+    input_image,
+    skip_pdf=None,
+    output_pdf,
+    output_text,
+    language: list,
+    engine_mode,
+    text_only: bool,
+    tessconfig: list,
+    timeout: float,
+    pagesegmode: int,
+    user_words,
+    user_patterns,
+    log,
+):
     '''Use Tesseract to render a PDF.
 
     input_image -- image to analyze
@@ -315,7 +325,7 @@ def generate_pdf(*, input_image, skip_pdf=None, output_pdf, output_text,
     args_tesseract = tess_base_args(language, engine_mode)
 
     if pagesegmode is not None:
-        args_tesseract.extend([psm(), str(pagesegmode)])
+        args_tesseract.extend(['--psm', str(pagesegmode)])
 
     if text_only and has_textonly_pdf():
         args_tesseract.extend(['-c', 'textonly_pdf=1'])
@@ -331,28 +341,18 @@ def generate_pdf(*, input_image, skip_pdf=None, output_pdf, output_text,
     # Reminder: test suite tesseract spoofers might break after any changes
     # to the number of order parameters here
 
-    args_tesseract.extend([
-        input_image,
-        prefix,
-        'pdf',
-        'txt'
-    ] + tessconfig)
+    args_tesseract.extend([input_image, prefix, 'pdf', 'txt'] + tessconfig)
 
     try:
         log.debug(args_tesseract)
-        stdout = check_output(
-            args_tesseract, stderr=STDOUT,
-            timeout=timeout)
+        stdout = check_output(args_tesseract, stderr=STDOUT, timeout=timeout)
         if os.path.exists(prefix + '.txt'):
             shutil.move(prefix + '.txt', output_text)
     except TimeoutExpired:
-        page_timedout(log, input_image)
+        page_timedout(log, input_image, timeout)
         use_skip_page(text_only, skip_pdf, output_pdf, output_text)
     except CalledProcessError as e:
         tesseract_log_output(log, e.output, input_image)
-        if b'read_params_file: parameter not found' in e.output:
-            raise TesseractConfigError() from e
-
         if b'Image too large' in e.output:
             use_skip_page(text_only, skip_pdf, output_pdf, output_text)
             return

src/ocrmypdf/exec/unpaper.py

@@ -18,14 +18,16 @@
 # unpaper documentation:
 # https://github.com/Flameeyes/unpaper/blob/master/doc/basic-concepts.md
 
-from subprocess import CalledProcessError, STDOUT, check_output
-from tempfile import NamedTemporaryFile
-import sys
 import os
+import shlex
+import subprocess
+import sys
 from functools import lru_cache
-from ..exceptions import MissingDependencyError
-from . import get_version
+from subprocess import PIPE, STDOUT, CalledProcessError
+from tempfile import TemporaryDirectory
 
+from . import get_version
+from ..exceptions import MissingDependencyError, SubprocessOutputError
 
 try:
     from PIL import Image
@@ -40,11 +42,7 @@ def version():
 
 
 def run(input_file, output_file, dpi, log, mode_args):
-    args_unpaper = [
-        'unpaper',
-        '-v',
-        '--dpi', str(dpi)
-    ] + mode_args
+    args_unpaper = ['unpaper', '-v', '--dpi', str(dpi)] + mode_args
 
     SUFFIXES = {'1': '.pbm', 'L': '.pgm', 'RGB': '.ppm'}
 
@@ -68,35 +66,64 @@ def run(input_file, output_file, dpi, log, mode_args):
         im.close()
         raise MissingDependencyError() from e
 
-    with NamedTemporaryFile(suffix=suffix) as input_pnm, \
-            NamedTemporaryFile(suffix=suffix, mode="r+b") as output_pnm:
+    with TemporaryDirectory() as tmpdir:
+        input_pnm = os.path.join(tmpdir, f'input{suffix}')
+        output_pnm = os.path.join(tmpdir, f'output{suffix}')
         im.save(input_pnm, format='PPM')
         im.close()
 
-        os.unlink(output_pnm.name)
-
-        args_unpaper.extend([input_pnm.name, output_pnm.name])
+        # To prevent any shenanigans from accepting arbitrary parameters in
+        # --unpaper-args, we:
+        # 1) run with cwd set to a tmpdir with only unpaper's files
+        # 2) forbid the use of '/' in arguments, to prevent changing paths
+        # 3) append absolute paths for the input and output file
+        # This should ensure that a user cannot clobber some other file with
+        # their unpaper arguments (whether intentionally or otherwise)
+        args_unpaper.extend([input_pnm, output_pnm])
         try:
-            stdout = check_output(
-                args_unpaper, close_fds=True,
-                universal_newlines=True, stderr=STDOUT,
-                )
+            proc = subprocess.run(
+                args_unpaper,
+                check=True,
+                close_fds=True,
+                universal_newlines=True,
+                stderr=STDOUT,
+                cwd=tmpdir,
+                stdout=PIPE,
+            )
         except CalledProcessError as e:
             log.debug(e.output)
             raise e from e
         else:
-            log.debug(stdout)
-            # unpaper sets dpi to 72
-            Image.open(output_pnm.name).save(output_file, dpi=(dpi, dpi))
+            log.debug(proc.stdout)
+            # unpaper sets dpi to 72; fix this
+            try:
+                Image.open(output_pnm).save(output_file, dpi=(dpi, dpi))
+            except (FileNotFoundError, OSError):
+                raise SubprocessOutputError(
+                    "unpaper: failed to produce the expected output file. Called with: "
+                    + str(args_unpaper)
+                ) from None
 
 
-def clean(input_file, output_file, dpi, log):
-    run(input_file, output_file, dpi, log, [
-        '--layout', 'none',
-        '--mask-scan-size', '100',  # don't blank out narrow columns
+def validate_custom_args(args: str):
+    unpaper_args = shlex.split(args)
+    if any('/' in arg for arg in unpaper_args):
+        raise ValueError('No filenames allowed in --unpaper-args')
+    return unpaper_args
+
+
+def clean(input_file, output_file, dpi, log, unpaper_args=None):
+    default_args = [
+        '--layout',
+        'none',
+        '--mask-scan-size',
+        '100',  # don't blank out narrow columns
         '--no-border-align',  # don't align visible content to borders
-        '--no-mask-center',   # don't center visible content within page
-        '--no-grayfilter',    # don't remove light gray areas
-        '--no-blackfilter',   # don't remove solid black areas
-        '--no-deskew',        # don't deskew
-    ])
+        '--no-mask-center',  # don't center visible content within page
+        '--no-grayfilter',  # don't remove light gray areas
+        '--no-blackfilter',  # don't remove solid black areas
+        '--no-deskew',  # don't deskew
+    ]
+    if not unpaper_args:
+        unpaper_args = default_args
+    run(input_file, output_file, dpi, log, unpaper_args)

src/ocrmypdf/helpers.py

@@ -15,22 +15,22 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from functools import partial
+import multiprocessing
+import os
+import sys
+import warnings
 from collections.abc import Iterable
 from contextlib import suppress
+from functools import partial, wraps
 from pathlib import Path
-import sys
-import os
-import multiprocessing
-import warnings
 
 
 def re_symlink(input_file, soft_link_name, log=None):
     """
     Helper function: relinks soft symbolic link if necessary
     """
-    input_file = fspath(input_file)  # For Py3.5
-    soft_link_name = fspath(soft_link_name)
+    input_file = os.fspath(input_file)
+    soft_link_name = os.fspath(soft_link_name)
     if log is None:
         prdebug = partial(print, file=sys.stderr)
     else:
@@ -38,32 +38,29 @@ def re_symlink(input_file, soft_link_name, log=None):
 
     # Guard against soft linking to oneself
     if input_file == soft_link_name:
-        prdebug("Warning: No symbolic link made. You are using " +
-                "the original data directory as the working directory.")
+        prdebug(
+            "Warning: No symbolic link made. You are using "
+            + "the original data directory as the working directory."
+        )
         return
 
     # Soft link already exists: delete for relink?
     if os.path.lexists(soft_link_name):
         # do not delete or overwrite real (non-soft link) file
         if not os.path.islink(soft_link_name):
-            raise FileExistsError(
-                "%s exists and is not a link" % soft_link_name)
+            raise FileExistsError("%s exists and is not a link" % soft_link_name)
         try:
             os.unlink(soft_link_name)
         except OSError:
             prdebug("Can't unlink %s" % (soft_link_name))
 
     if not os.path.exists(input_file):
-        raise FileNotFoundError(
-            "trying to create a broken symlink to %s" % input_file)
+        raise FileNotFoundError("trying to create a broken symlink to %s" % input_file)
 
     prdebug("os.symlink(%s, %s)" % (input_file, soft_link_name))
 
     # Create symbolic link using absolute path
-    os.symlink(
-        os.path.abspath(input_file),
-        soft_link_name
-    )
+    os.symlink(os.path.abspath(input_file), soft_link_name)
 
 
 def is_iterable_notstr(thing):
@@ -72,7 +69,7 @@ def is_iterable_notstr(thing):
 
 def page_number(input_file):
     """Get one-based page number implied by filename (000002.pdf -> 2)"""
-    return int(os.path.basename(fspath(input_file))[0:6])
+    return int(os.path.basename(os.fspath(input_file))[0:6])
 
 
 def available_cpu_count():
@@ -83,13 +80,14 @@ def available_cpu_count():
 
     try:
         import psutil
+
         return psutil.cpu_count()
     except (ImportError, AttributeError):
         pass
 
     warnings.warn(
-        "Could not get CPU count.  Assuming one (1) CPU."
-        "Use -j N to set manually.")
+        "Could not get CPU count.  Assuming one (1) CPU." "Use -j N to set manually."
+    )
     return 1
 
 
@@ -103,20 +101,15 @@ def is_file_writable(test_file):
     p = Path(test_file)
 
     if p.is_symlink():
-        # Python 3.5 does not accept parameters for Path.resolve() and behaves
-        # as if strict=True (throws an exception on failure). Python 3.6
-        # defaults to strict=False. This implements strict=False like behavior
-        # for Python 3.5.
-        if sys.version_info[0:2] <= (3, 5):
-            p = Path(os.path.realpath(fspath(p)))
-        else:
-            p = p.resolve(strict=False)
+        p = p.resolve(strict=False)
 
     # p.is_file() throws an exception in some cases
     if p.exists() and p.is_file():
         return os.access(
-            fspath(p), os.W_OK,
-            effective_ids=(os.access in os.supports_effective_ids))
+            os.fspath(p),
+            os.W_OK,
+            effective_ids=(os.access in os.supports_effective_ids),
+        )
     else:
         try:
             fp = p.open('wb')
@@ -129,42 +122,26 @@ def is_file_writable(test_file):
         return True
 
 
-if sys.version_info[0:2] <= (3, 5):
-    def fspath(path):
-        """https://www.python.org/dev/peps/pep-0519/#os"""
-        import pathlib
-        if isinstance(path, (str, bytes)):
-            return path
-
-        # Work from the object's type to match method resolution of other magic
-        # methods.
-        path_type = type(path)
-        try:
-            path = path_type.__fspath__(path)
-        except AttributeError:
-            # Added for Python 3.5 support.
-            if isinstance(path, pathlib.Path):
-                return str(path)
-            elif hasattr(path_type, '__fspath__'):
-                raise
-        else:
-            if isinstance(path, (str, bytes)):
-                return path
-            else:
-                raise TypeError("expected __fspath__() to return str or bytes, "
-                                "not " + type(path).__name__)
-
-        raise TypeError(
-            "expected str, bytes, pathlib.Path or os.PathLike object, not "
-            + path_type.__name__)
-
-else:
-    fspath = os.fspath
-
-
 def flatten_groups(groups):
     for obj in groups:
         if is_iterable_notstr(obj):
             yield from obj
         else:
             yield obj
+
+
+def deprecated(func):
+    """Warn that function is deprecated"""
+
+    @wraps(func)
+    def new_func(*args, **kwargs):
+        warnings.simplefilter('always', DeprecationWarning)  # turn off filter
+        warnings.warn(
+            "Call to deprecated function {}.".format(func.__name__),
+            category=DeprecationWarning,
+            stacklevel=2,
+        )
+        warnings.simplefilter('default', DeprecationWarning)  # reset filter
+        return func(*args, **kwargs)
+
+    return new_func

src/ocrmypdf/hocrtransform.py

@@ -28,14 +28,14 @@
 # TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-from reportlab.pdfgen.canvas import Canvas
-from reportlab.lib.units import inch
-from xml.etree import ElementTree
-from collections import namedtuple
-from math import atan, sin, cos
-import re
 import argparse
+import re
+from collections import namedtuple
+from math import atan, cos, sin
+from xml.etree import ElementTree
 
+from reportlab.lib.units import inch
+from reportlab.pdfgen.canvas import Canvas
 
 Rect = namedtuple('Rect', ['x1', 'y1', 'x2', 'y2'])
 
@@ -44,7 +44,7 @@ class HocrTransformError(Exception):
     pass
 
 
-class HocrTransform():
+class HocrTransform:
 
     """
     A class for converting documents from the hOCR format.
@@ -53,17 +53,16 @@ class HocrTransform():
     """
 
     box_pattern = re.compile(r'bbox((\s+\d+){4})')
-    baseline_pattern = re.compile(r'''
+    baseline_pattern = re.compile(
+        r'''
         baseline \s+
         ([\-\+]?\d*\.?\d*) \s+  # +/- decimal float
-        ([\-\+]?\d+)            # +/- int''', re.VERBOSE)
-    ligatures = str.maketrans({
-        'ff': 'ff',
-        'ffi': 'f‌f‌i',
-        'ffl': 'f‌f‌l',
-        'fi': 'fi',
-        'fl': 'fl',
-    })
+        ([\-\+]?\d+)            # +/- int''',
+        re.VERBOSE,
+    )
+    ligatures = str.maketrans(
+        {'ff': 'ff', 'ffi': 'f‌f‌i', 'ffl': 'f‌f‌l', 'fi': 'fi', 'fl': 'fl'}
+    )
 
     def __init__(self, hocrFileName, dpi):
         self.dpi = dpi
@@ -78,8 +77,7 @@ class HocrTransform():
 
         # get dimension in pt (not pixel!!!!) of the OCRed image
         self.width, self.height = None, None
-        for div in self.hocr.findall(
-                ".//%sdiv[@class='ocr_page']" % (self.xmlns)):
+        for div in self.hocr.findall(".//%sdiv[@class='ocr_page']" % (self.xmlns)):
             coords = self.element_coordinates(div)
             pt_coords = self.pt_from_pixel(coords)
             self.width = pt_coords.x2 - pt_coords.x1
@@ -144,8 +142,7 @@ class HocrTransform():
         """
         Returns the quantity in PDF units (pt) given quantity in pixels
         """
-        return Rect._make(
-            (c / self.dpi * inch) for c in pxl)
+        return Rect._make((c / self.dpi * inch) for c in pxl)
 
     @classmethod
     def replace_unsupported_chars(cls, s):
@@ -156,8 +153,15 @@ class HocrTransform():
         """
         return s.translate(cls.ligatures)
 
-    def to_pdf(self, outFileName, imageFileName=None, showBoundingboxes=False,
-               fontname="Helvetica", invisibleText=False, interwordSpaces=False):
+    def to_pdf(
+        self,
+        outFileName,
+        imageFileName=None,
+        showBoundingboxes=False,
+        fontname="Helvetica",
+        invisibleText=False,
+        interwordSpaces=False,
+    ):
         """
         Creates a PDF file with an image superimposed on top of the text.
         Text is positioned according to the bounding box of the lines in
@@ -168,17 +172,15 @@ class HocrTransform():
         """
         # create the PDF file
         # page size in points (1/72 in.)
-        pdf = Canvas(
-            outFileName, pagesize=(self.width, self.height), pageCompression=1)
+        pdf = Canvas(outFileName, pagesize=(self.width, self.height), pageCompression=1)
 
         # draw bounding box for each paragraph
         # light blue for bounding box of paragraph
         pdf.setStrokeColorRGB(0, 1, 1)
         # light blue for bounding box of paragraph
         pdf.setFillColorRGB(0, 1, 1)
-        pdf.setLineWidth(0)		# no line for bounding box
-        for elem in self.hocr.findall(
-                ".//%sp[@class='%s']" % (self.xmlns, "ocr_par")):
+        pdf.setLineWidth(0)  # no line for bounding box
+        for elem in self.hocr.findall(".//%sp[@class='%s']" % (self.xmlns, "ocr_par")):
 
             elemtxt = self._get_element_text(elem).rstrip()
             if len(elemtxt) == 0:
@@ -190,38 +192,58 @@ class HocrTransform():
             # draw the bbox border
             if showBoundingboxes:
                 pdf.rect(
-                    pt.x1, self.height - pt.y2, pt.x2 - pt.x1, pt.y2 - pt.y1,
-                    fill=1)
+                    pt.x1, self.height - pt.y2, pt.x2 - pt.x1, pt.y2 - pt.y1, fill=1
+                )
 
         found_lines = False
         for line in self.hocr.findall(
-                ".//%sspan[@class='%s']" % (self.xmlns, "ocr_line")):
+            ".//%sspan[@class='%s']" % (self.xmlns, "ocr_line")
+        ):
             found_lines = True
-            self._do_line(pdf, line, "ocrx_word", fontname, invisibleText,
-                          interwordSpaces, showBoundingboxes)
+            self._do_line(
+                pdf,
+                line,
+                "ocrx_word",
+                fontname,
+                invisibleText,
+                interwordSpaces,
+                showBoundingboxes,
+            )
 
         if not found_lines:
             # Tesseract did not report any lines (just words)
             root = self.hocr.find(".//%sdiv[@class='%s']" % (self.xmlns, "ocr_page"))
-            self._do_line(pdf, root, "ocrx_word", fontname, invisibleText,
-                          interwordSpaces, showBoundingboxes)
+            self._do_line(
+                pdf,
+                root,
+                "ocrx_word",
+                fontname,
+                invisibleText,
+                interwordSpaces,
+                showBoundingboxes,
+            )
         # put the image on the page, scaled to fill the page
         if imageFileName is not None:
-            pdf.drawImage(imageFileName, 0, 0,
-                          width=self.width, height=self.height)
+            pdf.drawImage(imageFileName, 0, 0, width=self.width, height=self.height)
 
         # finish up the page and save it
         pdf.showPage()
         pdf.save()
 
-
     @classmethod
     def polyval(cls, poly, x):
         return x * poly[0] + poly[1]
 
-
-    def _do_line(self, pdf, line, elemclass, fontname, invisibleText,
-                 interwordSpaces, showBoundingboxes):
+    def _do_line(
+        self,
+        pdf,
+        line,
+        elemclass,
+        fontname,
+        invisibleText,
+        interwordSpaces,
+        showBoundingboxes,
+    ):
         pxl_line_coords = self.element_coordinates(line)
         line_box = self.pt_from_pixel(pxl_line_coords)
         line_height = line_box.y2 - line_box.y1
@@ -254,23 +276,20 @@ class HocrTransform():
             pdf.setLineWidth(0.5)
             # negate slope because it is defined as a rise/run in pixel
             # coordinates and page coordinates have the y axis flipped
-            pdf.line(line_box.x1,
-                     baseline_y2,
-                     line_box.x2,
-                     self.polyval((-slope, baseline_y2),
-                                  line_box.x2 - line_box.x1))
+            pdf.line(
+                line_box.x1,
+                baseline_y2,
+                line_box.x2,
+                self.polyval((-slope, baseline_y2), line_box.x2 - line_box.x1),
+            )
             # light green for bounding box of word/line
             pdf.setDash(6, 3)
             pdf.setStrokeColorRGB(1, 0, 0)
 
-        text.setTextTransform(
-            cos_a, -sin_a, sin_a, cos_a,
-            line_box.x1, baseline_y2
-        )
+        text.setTextTransform(cos_a, -sin_a, sin_a, cos_a, line_box.x1, baseline_y2)
         pdf.setFillColorRGB(0, 0, 0)  # text in black
 
-        elements = line.findall(
-                ".//%sspan[@class='%s']" % (self.xmlns, elemclass))
+        elements = line.findall(".//%sspan[@class='%s']" % (self.xmlns, elemclass))
         for elem in elements:
             elemtxt = self._get_element_text(elem).strip()
             elemtxt = self.replace_unsupported_chars(elemtxt)
@@ -287,22 +306,22 @@ class HocrTransform():
                 # though it would look better, because it will interfere with
                 # naive text extraction. \n does not work either.
                 elemtxt += ' '
-                box = Rect._make((
-                    box.x1,
-                    line_box.y1,
-                    box.x2 + pdf.stringWidth(' ', fontname, line_height),
-                    line_box.y2))
+                box = Rect._make(
+                    (
+                        box.x1,
+                        line_box.y1,
+                        box.x2 + pdf.stringWidth(' ', fontname, line_height),
+                        line_box.y2,
+                    )
+                )
             box_width = box.x2 - box.x1
             font_width = pdf.stringWidth(elemtxt, fontname, fontsize)
 
             # draw the bbox border
             if showBoundingboxes:
                 pdf.rect(
-                    box.x1,
-                    self.height - line_box.y2,
-                    box_width,
-                    line_height,
-                    fill=0)
+                    box.x1, self.height - line_box.y2, box_width, line_height, fill=0
+                )
 
             # Adjust relative position of cursor
             # This is equivalent to:
@@ -331,19 +350,40 @@ class HocrTransform():
 
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description='Convert hocr file to PDF')
-    parser.add_argument('-b', '--boundingboxes', action="store_true",
-                        default=False, help='Show bounding boxes borders')
-    parser.add_argument('-r', '--resolution', type=int,
-                        default=300,
-                        help='Resolution of the image that was OCRed')
-    parser.add_argument('-i', '--image', default=None,
-                        help='Path to the image to be placed above the text')
-    parser.add_argument('--interword-spaces', action='store_true',
-                         default=False, help='Add spaces between words')
-    parser.add_argument('hocrfile', help='Path to the hocr file to be parsed')
     parser.add_argument(
-        'outputfile', help='Path to the PDF file to be generated')
+        '-b',
+        '--boundingboxes',
+        action="store_true",
+        default=False,
+        help='Show bounding boxes borders',
+    )
+    parser.add_argument(
+        '-r',
+        '--resolution',
+        type=int,
+        default=300,
+        help='Resolution of the image that was OCRed',
+    )
+    parser.add_argument(
+        '-i',
+        '--image',
+        default=None,
+        help='Path to the image to be placed above the text',
+    )
+    parser.add_argument(
+        '--interword-spaces',
+        action='store_true',
+        default=False,
+        help='Add spaces between words',
+    )
+    parser.add_argument('hocrfile', help='Path to the hocr file to be parsed')
+    parser.add_argument('outputfile', help='Path to the PDF file to be generated')
     args = parser.parse_args()
 
     hocr = HocrTransform(args.hocrfile, args.resolution)
-    hocr.to_pdf(args.outputfile, args.image, args.boundingboxes, interwordSpaces=args.interword_spaces)
+    hocr.to_pdf(
+        args.outputfile,
+        args.image,
+        args.boundingboxes,
+        interwordSpaces=args.interword_spaces,
+    )

src/ocrmypdf/leptonica.py

@@ -21,23 +21,27 @@
 # Python FFI wrapper for Leptonica library
 
 import argparse
-import sys
-import os
 import logging
+import os
+import sys
 import warnings
-from tempfile import TemporaryFile
+from collections.abc import Sequence
+from contextlib import suppress
 from ctypes.util import find_library
 from functools import lru_cache
+from io import BytesIO
+from os import fspath
+from tempfile import TemporaryFile
 
 from .lib._leptonica import ffi
-from .helpers import fspath
 
-# pylint: disable=w0212
-
-lept = ffi.dlopen(find_library('lept'))
+# pylint: disable=protected-access
 
 logger = logging.getLogger(__name__)
 
+lept = ffi.dlopen(find_library('lept'))
+lept.setMsgSeverity(lept.L_SEVERITY_WARNING)
+
 
 def stderr(*objs):
     """Shorthand print to stderr."""
@@ -45,12 +49,13 @@ def stderr(*objs):
 
 
 class _LeptonicaErrorTrap:
-    """Context manager to trap errors reported by Leptonica.
+    """
+    Context manager to trap errors reported by Leptonica.
 
-    Leptonica's error return codes are unreliable to the point of being
-    almost useless.  It does, however, write errors to stderr provided that is
-    not disabled at its compile time.  Fortunately this is done using error
-    macros so it is very self-consistent.
+    Leptonica's error return codes don't provide much informatino about what
+    went wrong. Leptonica does, however, write more detailed errors to stderr
+    (provided this is not disabled at compile time). The Leptonica source
+    code is very consistent in its use of macros to generate errors.
 
     This context manager redirects stderr to a temporary file which is then
     read and parsed for error messages.  As a side benefit, debug messages
@@ -64,14 +69,14 @@ class _LeptonicaErrorTrap:
 
     def __enter__(self):
         from io import UnsupportedOperation
+
         self.tmpfile = TemporaryFile()
 
         # Save the old stderr, and redirect stderr to temporary file
         sys.stderr.flush()
         try:
             self.copy_of_stderr = os.dup(sys.stderr.fileno())
-            os.dup2(self.tmpfile.fileno(), sys.stderr.fileno(),
-                    inheritable=False)
+            os.dup2(self.tmpfile.fileno(), sys.stderr.fileno(), inheritable=False)
         except UnsupportedOperation:
             self.copy_of_stderr = None
         return
@@ -102,6 +107,8 @@ class _LeptonicaErrorTrap:
                 raise FileNotFoundError()
             if 'pixWrite: stream not opened' in leptonica_output:
                 raise LeptonicaIOError()
+            if 'index not valid' in leptonica_output:
+                raise IndexError()
             raise LeptonicaError(leptonica_output)
 
         return False
@@ -115,8 +122,45 @@ class LeptonicaIOError(LeptonicaError):
     pass
 
 
-class Pix:
-    """Wrapper around leptonica's PIX object.
+class LeptonicaObject:
+    """General wrapper for Leptonica objects
+
+    When Leptonica returns an object, we bundled it in a wrapper class, which
+    manages its memory. The wrapper class assumes that it will be calling some
+    sort of lept.thingDestroy() function when the instance is deleted. Most
+    Leptonica objects are reference counted, and destroy decrements the
+    refcount.
+
+    Most of the time, when Leptonica returns something, we wrap and it the job
+    is done. When wrapping objects that came from a Leptonica container, like
+    a PIXA returning PIX, the subclass must clone the object before passing it
+    here, to maintain the reference count.
+
+    CFFI ensures that the destroy function is called at garbage collection time
+    so we do not need to mess with __del__.
+    """
+
+    cdata_destroy = lambda cdata: None
+    LEPTONICA_TYPENAME = ''
+
+    def __init__(self, cdata):
+        if not cdata:
+            raise ValueError('Tried to wrap a NULL ' + self.LEPTONICA_TYPENAME)
+        self._cdata = ffi.gc(cdata, self._destroy)
+
+    @classmethod
+    def _destroy(cls, cdata):
+        """Destroy some cdata"""
+        # Leptonica API uses double-pointers for its destroy APIs to prevent
+        # dangling pointers. This means we need to put our single pointer,
+        # cdata, in a temporary CDATA**.
+        pp = ffi.new('{} **'.format(cls.LEPTONICA_TYPENAME), cdata)
+        cls.cdata_destroy(pp)
+
+
+class Pix(LeptonicaObject):
+    """
+    Wrapper around leptonica's PIX object.
 
     Leptonica uses referencing counting on PIX objects. Also, many Leptonica
     functions return the original object with an increased reference count
@@ -133,18 +177,21 @@ class Pix:
     modified objects.  This allows convenient chaining:
 
     >>>   Pix.open('filename.jpg').scale((0.5, 0.5)).deskew().show()
-
     """
 
-    def __init__(self, pix):
-        self._pix = ffi.gc(pix, Pix._pix_destroy)
+    LEPTONICA_TYPENAME = "PIX"
+    cdata_destroy = lept.pixDestroy
 
     def __repr__(self):
-        if self._pix:
+        if self._cdata:
             s = "<leptonica.Pix image size={0}x{1} depth={2}{4} at 0x{3:x}>"
-            return s.format(self._pix.w, self._pix.h, self._pix.d,
-                            int(ffi.cast('intptr_t', self._pix)),
-                            '(colormapped)' if self._pix.colormap else '')
+            return s.format(
+                self._cdata.w,
+                self._cdata.h,
+                self._cdata.d,
+                int(ffi.cast('intptr_t', self._cdata)),
+                '(colormapped)' if self._cdata.colormap else '',
+            )
         else:
             return "<leptonica.Pix image NULL>"
 
@@ -157,7 +204,7 @@ class Pix:
         data = ffi.new('l_uint8 **')
         size = ffi.new('size_t *')
 
-        err = lept.pixWriteMemPng(data, size, self._pix, 0)
+        err = lept.pixWriteMemPng(data, size, self._cdata, 0)
         if err != 0:
             raise LeptonicaIOError("pixWriteMemPng")
 
@@ -168,7 +215,7 @@ class Pix:
         data = ffi.new('l_uint32 **')
         size = ffi.new('size_t *')
 
-        err = lept.pixSerializeToMemory(self._pix, data, size)
+        err = lept.pixSerializeToMemory(self._cdata, data, size)
         if err != 0:
             raise LeptonicaIOError("pixSerializeToMemory")
 
@@ -185,32 +232,38 @@ class Pix:
         cdata_bytes = ffi.new('char[]', state['data'])
         cdata_uint32 = ffi.cast('l_uint32 *', cdata_bytes)
 
-        pix = lept.pixDeserializeFromMemory(
-            cdata_uint32, len(state['data']))
+        pix = lept.pixDeserializeFromMemory(cdata_uint32, len(state['data']))
         Pix.__init__(self, pix)
 
     def __eq__(self, other):
-        return self.__getstate__() == other.__getstate__()
+        if not isinstance(other, Pix):
+            return NotImplemented
+        same = ffi.new('l_int32 *', 0)
+        with _LeptonicaErrorTrap():
+            err = lept.pixEqual(self._cdata, other._cdata, same)
+            if err:
+                raise TypeError()
+        return bool(same[0])
 
     @property
     def width(self):
-        return self._pix.w
+        return self._cdata.w
 
     @property
     def height(self):
-        return self._pix.h
+        return self._cdata.h
 
     @property
     def depth(self):
-        return self._pix.d
+        return self._cdata.d
 
     @property
     def size(self):
-        return (self._pix.w, self._pix.h)
+        return (self._cdata.w, self._cdata.h)
 
     @property
     def info(self):
-        return {'dpi': (self._pix.xres, self._pix.yres)}
+        return {'dpi': (self._cdata.xres, self._cdata.yres)}
 
     @property
     def mode(self):
@@ -219,7 +272,7 @@ class Pix:
             return '1'
         elif self.depth >= 16:
             return 'RGB'
-        elif not self._pix.colormap:
+        elif not self._cdata.colormap:
             return 'L'
         else:
             return 'P'
@@ -240,8 +293,7 @@ class Pix:
         with _LeptonicaErrorTrap():
             return cls(lept.pixRead(os.fsencode(filename)))
 
-    def write_implied_format(
-            self, path, jpeg_quality=0, jpeg_progressive=0):
+    def write_implied_format(self, path, jpeg_quality=0, jpeg_progressive=0):
         """Write pix to the filename, with the extension indicating format.
 
         jpeg_quality -- quality (iff JPEG; 1 - 100, 0 for default)
@@ -250,11 +302,22 @@ class Pix:
         filename = fspath(path)
         with _LeptonicaErrorTrap():
             lept.pixWriteImpliedFormat(
-                os.fsencode(filename),
-                self._pix, jpeg_quality, jpeg_progressive)
+                os.fsencode(filename), self._cdata, jpeg_quality, jpeg_progressive
+            )
+
+    @classmethod
+    def frompil(self, pillow_image):
+        """Create a copy of a PIL.Image from this Pix"""
+        bio = BytesIO()
+        pillow_image.save(bio, format='png', compress_level=1)
+        py_buffer = bio.getbuffer()
+        c_buffer = ffi.from_buffer(py_buffer)
+        with _LeptonicaErrorTrap():
+            pix = Pix(lept.pixReadMem(c_buffer, len(c_buffer)))
+            return pix
 
     def topil(self):
-        "Returns a PIL.Image version of this Pix"
+        """Returns a PIL.Image version of this Pix"""
         from PIL import Image
 
         # Leptonica manages data in words, so it implicitly does an endian
@@ -267,17 +330,17 @@ class Pix:
                 raw_mode = 'ABGR'
             elif self.mode == '1':
                 raw_mode = '1;I'
-                pix = Pix(lept.pixEndianByteSwapNew(pix._pix))
+                pix = Pix(lept.pixEndianByteSwapNew(pix._cdata))
             else:
                 raw_mode = self.mode
-                pix = Pix(lept.pixEndianByteSwapNew(pix._pix))
+                pix = Pix(lept.pixEndianByteSwapNew(pix._cdata))
         else:
             raw_mode = self.mode  # no endian swap needed
 
-        size = (pix._pix.w, pix._pix.h)
-        bytecount = pix._pix.wpl * 4 * pix._pix.h
-        buf = ffi.buffer(pix._pix.data, bytecount)
-        stride = pix._pix.wpl * 4
+        size = (pix._cdata.w, pix._cdata.h)
+        bytecount = pix._cdata.wpl * 4 * pix._cdata.h
+        buf = ffi.buffer(pix._cdata.data, bytecount)
+        stride = pix._cdata.wpl * 4
 
         im = Image.frombytes(self.mode, size, buf, 'raw', raw_mode, stride)
 
@@ -296,21 +359,21 @@ class Pix:
             for skew angle
         """
         with _LeptonicaErrorTrap():
-            return Pix(lept.pixDeskew(self._pix, reduction_factor))
+            return Pix(lept.pixDeskew(self._cdata, reduction_factor))
 
     def scale(self, scale_xy):
         "Returns the pix object rescaled according to the proportions given."
         with _LeptonicaErrorTrap():
-            return Pix(lept.pixScale(self._pix, scale_xy[0], scale_xy[1]))
+            return Pix(lept.pixScale(self._cdata, scale_xy[0], scale_xy[1]))
 
     def rotate180(self):
         with _LeptonicaErrorTrap():
-            return Pix(lept.pixRotate180(ffi.NULL, self._pix))
+            return Pix(lept.pixRotate180(ffi.NULL, self._cdata))
 
     def rotate_orth(self, quads):
         "Orthographic rotation, quads: 0-3, number of clockwise rotations"
         with _LeptonicaErrorTrap():
-            return Pix(lept.pixRotateOrth(self._pix, quads))
+            return Pix(lept.pixRotateOrth(self._cdata, quads))
 
     def find_skew(self):
         """Returns a tuple (deskew angle in degrees, confidence value).
@@ -320,7 +383,7 @@ class Pix:
         with _LeptonicaErrorTrap():
             angle = ffi.new('float *', 0.0)
             confidence = ffi.new('float *', 0.0)
-            result = lept.pixFindSkew(self._pix, angle, confidence)
+            result = lept.pixFindSkew(self._cdata, angle, confidence)
             if result == 0:
                 return (angle[0], confidence[0])
             else:
@@ -328,7 +391,7 @@ class Pix:
 
     def convert_rgb_to_luminance(self):
         with _LeptonicaErrorTrap():
-            gray_pix = lept.pixConvertRGBToLuminance(self._pix)
+            gray_pix = lept.pixConvertRGBToLuminance(self._cdata)
             if gray_pix:
                 return Pix(gray_pix)
             return None
@@ -341,114 +404,165 @@ class Pix:
 
         """
         with _LeptonicaErrorTrap():
-            return Pix(lept.pixRemoveColormapGeneral(
-                    self._pix, removal_type, lept.L_COPY))
+            return Pix(
+                lept.pixRemoveColormapGeneral(self._cdata, removal_type, lept.L_COPY)
+            )
 
     def otsu_adaptive_threshold(
-            self, tile_size=(300, 300), kernel_size=(4, 4), scorefract=0.1):
+        self, tile_size=(300, 300), kernel_size=(4, 4), scorefract=0.1
+    ):
         with _LeptonicaErrorTrap():
             sx, sy = tile_size
             smoothx, smoothy = kernel_size
             p_pix = ffi.new('PIX **')
 
+            pix = Pix(lept.pixConvertTo8(self._cdata, 0))
             result = lept.pixOtsuAdaptiveThreshold(
-                self._pix,
-                sx, sy,
-                smoothx, smoothy,
-                scorefract,
-                ffi.NULL,
-                p_pix)
+                pix._cdata, sx, sy, smoothx, smoothy, scorefract, ffi.NULL, p_pix
+            )
             if result == 0:
                 return Pix(p_pix[0])
             else:
                 return None
 
     def otsu_threshold_on_background_norm(
-            self, mask=None, tile_size=(10, 15), thresh=100, mincount=50,
-            bgval=255, kernel_size=(2, 2), scorefract=0.1):
+        self,
+        mask=None,
+        tile_size=(10, 15),
+        thresh=100,
+        mincount=50,
+        bgval=255,
+        kernel_size=(2, 2),
+        scorefract=0.1,
+    ):
         with _LeptonicaErrorTrap():
             sx, sy = tile_size
             smoothx, smoothy = kernel_size
-            if mask is None:
-                mask = ffi.NULL
+            mask = ffi.NULL
             if isinstance(mask, Pix):
-                mask = mask._pix
+                mask = mask._cdata
 
+            pix = Pix(lept.pixConvertTo8(self._cdata, 0))
             thresh_pix = lept.pixOtsuThreshOnBackgroundNorm(
-                self._pix,
+                pix._cdata,
                 mask,
-                sx, sy,
-                thresh, mincount, bgval,
-                smoothx, smoothy,
+                sx,
+                sy,
+                thresh,
+                mincount,
+                bgval,
+                smoothx,
+                smoothy,
                 scorefract,
-                ffi.NULL
-                )
-            if thresh_pix == ffi.NULL:
-                return None
+                ffi.NULL,
+            )
+            return Pix(thresh_pix)
+
+    def masked_threshold_on_background_norm(
+        self,
+        mask=None,
+        tile_size=(10, 15),
+        thresh=100,
+        mincount=50,
+        kernel_size=(2, 2),
+        scorefract=0.1,
+    ):
+        with _LeptonicaErrorTrap():
+            sx, sy = tile_size
+            smoothx, smoothy = kernel_size
+            mask = ffi.NULL
+            if isinstance(mask, Pix):
+                mask = mask._cdata
+
+            pix = Pix(lept.pixConvertTo8(self._cdata, 0))
+            thresh_pix = lept.pixMaskedThreshOnBackgroundNorm(
+                pix._cdata,
+                mask,
+                sx,
+                sy,
+                thresh,
+                mincount,
+                smoothx,
+                smoothy,
+                scorefract,
+                ffi.NULL,
+            )
             return Pix(thresh_pix)
 
     def crop_to_foreground(
-            self, threshold=128, mindist=70, erasedist=30, pagenum=0,
-            showmorph=0, display=0, pdfdir=ffi.NULL):
+        self,
+        threshold=128,
+        mindist=70,
+        erasedist=30,
+        pagenum=0,
+        showmorph=0,
+        display=0,
+        pdfdir=ffi.NULL,
+    ):
         with _LeptonicaErrorTrap():
-            cropbox = Box(lept.pixFindPageForeground(
-                self._pix,
-                threshold,
-                mindist,
-                erasedist,
-                pagenum,
-                showmorph,
-                display,
-                pdfdir))
+            cropbox = Box(
+                lept.pixFindPageForeground(
+                    self._cdata,
+                    threshold,
+                    mindist,
+                    erasedist,
+                    pagenum,
+                    showmorph,
+                    display,
+                    pdfdir,
+                )
+            )
 
-            print(repr(cropbox))
-
-            cropped_pix = lept.pixClipRectangle(
-                self._pix,
-                cropbox._box,
-                ffi.NULL)
+            cropped_pix = lept.pixClipRectangle(self._cdata, cropbox._cdata, ffi.NULL)
 
             return Pix(cropped_pix)
 
     def clean_background_to_white(
-            self, mask=None, grayscale=None, gamma=1.0, black=0, white=255):
+        self, mask=None, grayscale=None, gamma=1.0, black=0, white=255
+    ):
         with _LeptonicaErrorTrap():
-            return Pix(lept.pixCleanBackgroundToWhite(
-                self._pix,
-                mask or ffi.NULL,
-                grayscale or ffi.NULL,
-                gamma,
-                black,
-                white))
+            return Pix(
+                lept.pixCleanBackgroundToWhite(
+                    self._cdata,
+                    mask or ffi.NULL,
+                    grayscale or ffi.NULL,
+                    gamma,
+                    black,
+                    white,
+                )
+            )
 
     def gamma_trc(self, gamma=1.0, minval=0, maxval=255):
         with _LeptonicaErrorTrap():
-            return Pix(lept.pixGammaTRC(
-                ffi.NULL,
-                self._pix,
-                gamma,
-                minval,
-                maxval
-                ))
+            return Pix(lept.pixGammaTRC(ffi.NULL, self._cdata, gamma, minval, maxval))
 
     def background_norm(
-            self, mask=None, grayscale=None, tile_size=(10, 15), fg_threshold=60,
-            min_count=40, bg_val=200, smooth_kernel=(2, 1)):
+        self,
+        mask=None,
+        grayscale=None,
+        tile_size=(10, 15),
+        fg_threshold=60,
+        min_count=40,
+        bg_val=200,
+        smooth_kernel=(2, 1),
+    ):
         # Background norm doesn't work on color mapped Pix, so remove colormap
         target_pix = self.remove_colormap(lept.REMOVE_CMAP_BASED_ON_SRC)
         with _LeptonicaErrorTrap():
-            return Pix(lept.pixBackgroundNorm(
-                target_pix._pix,
-                mask or ffi.NULL,
-                grayscale or ffi.NULL,
-                tile_size[0],
-                tile_size[1],
-                fg_threshold,
-                min_count,
-                bg_val,
-                smooth_kernel[0],
-                smooth_kernel[1]
-            ))
+            return Pix(
+                lept.pixBackgroundNorm(
+                    target_pix._cdata,
+                    mask or ffi.NULL,
+                    grayscale or ffi.NULL,
+                    tile_size[0],
+                    tile_size[1],
+                    fg_threshold,
+                    min_count,
+                    bg_val,
+                    smooth_kernel[0],
+                    smooth_kernel[1],
+                )
+            )
 
     @staticmethod
     @lru_cache(maxsize=1)
@@ -462,53 +576,92 @@ class Pix:
             # implementation of pixCorrelationBinary that overflows on larger
             # images.  Ubuntu 14.04/trusty has 1.70. Ubuntu PPA
             # ppa:alex-p/tesseract-ocr has leptonlib 1.75.
-            pix1_count = ffi.new('l_int32 *')
-            pix2_count = ffi.new('l_int32 *')
-            pixn_count = ffi.new('l_int32 *')
-            tab8 = Pix.make_pixel_sum_tab8()
+            raise LeptonicaError("Leptonica version is too old")
 
-            lept.pixCountPixels(pix1._pix, pix1_count, tab8)
-            lept.pixCountPixels(pix2._pix, pix2_count, tab8)
-            pixn = Pix(lept.pixAnd(ffi.NULL, pix1._pix, pix2._pix))
-            lept.pixCountPixels(pixn._pix, pixn_count, tab8)
-
-            # Python converts these int32s to larger units as needed
-            # to avoid overflow. Overflow happens easily here.
-            correlation = (
-                    (pixn_count[0] * pixn_count[0]) /
-                    (pix1_count[0] * pix2_count[0])
-                    )
-            return correlation
-        else:
-            correlation = ffi.new('float *', 0.0)
-            result = lept.pixCorrelationBinary(pix1._pix, pix2._pix,
-                                               correlation)
-            if result != 0:
-                raise LeptonicaError("Correlation failed")
-            return correlation[0]
+        correlation = ffi.new('float *', 0.0)
+        result = lept.pixCorrelationBinary(pix1._cdata, pix2._cdata, correlation)
+        if result != 0:
+            raise LeptonicaError("Correlation failed")
+        return correlation[0]
 
     def generate_pdf_ci_data(self, type_, quality):
         "Convert to PDF data, with transcoding"
         p_compdata = ffi.new('L_COMP_DATA **')
-        result = lept.pixGenerateCIData(self._pix, type_, quality, 0,
-                                        p_compdata)
+        result = lept.pixGenerateCIData(self._cdata, type_, quality, 0, p_compdata)
         if result != 0:
             raise LeptonicaError("Generate PDF data failed")
         return CompressedData(p_compdata[0])
 
     def invert(self):
-        return Pix(lept.pixInvert(ffi.NULL, self._pix))
+        return Pix(lept.pixInvert(ffi.NULL, self._cdata))
 
-    @staticmethod
-    def _pix_destroy(pix):
-        p_pix = ffi.new('PIX **', pix)
-        lept.pixDestroy(p_pix)
-        # print('pix destroy ' + repr(pix))
+    def locate_barcodes(self):
+        try:
+            with _LeptonicaErrorTrap():
+                pix = Pix(lept.pixConvertTo8(self._cdata, 0))
+                pixa_candidates = PixArray(lept.pixExtractBarcodes(pix._cdata, 0))
+                if not pixa_candidates:
+                    return
+                sarray = StringArray(
+                    lept.pixReadBarcodes(
+                        pixa_candidates._cdata,
+                        lept.L_BF_ANY,
+                        lept.L_USE_WIDTHS,
+                        ffi.NULL,
+                        0,
+                    )
+                )
+        except (LeptonicaError, ValueError, IndexError):
+            return
+        finally:
+            with suppress(FileNotFoundError):
+                os.unlink('junkpixt.png')  # leptonica may produce this
+                os.unlink('junkpixt')
+
+        for n, s in enumerate(sarray):
+            decoded = s.decode()
+            if decoded.strip() == '':
+                continue
+            box = pixa_candidates.get_box(n)
+            left, top = box.x, box.y
+            right, bottom = box.x + box.w, box.y + box.h
+            yield (decoded, (left, top, right, bottom))
+
+    def despeckle(self, size):
+        if size == 2:
+            speckle2 = """
+                oooo
+                oC o
+                o  o
+                oooo
+                """
+            sel1 = Sel.from_selstr(speckle2, 'speckle2')
+            sel2 = Sel.create_brick(2, 2, 0, 0, lept.SEL_HIT)
+        elif size == 3:
+            speckle3 = """
+                ooooo
+                oC  o
+                o   o
+                o   o
+                ooooo
+                """
+            sel1 = Sel.from_selstr(speckle3, 'speckle3')
+            sel2 = Sel.create_brick(3, 3, 0, 0, lept.SEL_HIT)
+        else:
+            raise ValueError(size)
+
+        pixhmt = Pix(lept.pixHMT(ffi.NULL, self._cdata, sel1._cdata))
+        pixdilated = Pix(lept.pixDilate(ffi.NULL, pixhmt._cdata, sel2._cdata))
+
+        pixsub = Pix(lept.pixSubtract(ffi.NULL, self._cdata, pixdilated._cdata))
+        return pixsub
 
 
-class CompressedData:
-    def __init__(self, compdata):
-        self._compdata = ffi.gc(compdata, CompressedData._destroy)
+class CompressedData(LeptonicaObject):
+    """Wrapper for L_COMP_DATA - abstract compressed image data"""
+
+    LEPTONICA_TYPENAME = 'L_COMP_DATA'
+    cdata_destroy = lept.l_CIDataDestroy
 
     @classmethod
     def open(cls, path, jpeg_quality=75):
@@ -517,70 +670,150 @@ class CompressedData:
 
         p_compdata = ffi.new('L_COMP_DATA **')
         result = lept.l_generateCIDataForPdf(
-            os.fsencode(filename), ffi.NULL, jpeg_quality, p_compdata)
+            os.fsencode(filename), ffi.NULL, jpeg_quality, p_compdata
+        )
         if result != 0:
             raise LeptonicaError("CompressedData.open")
         return CompressedData(p_compdata[0])
 
     def __len__(self):
-        return self._compdata.nbytescomp
+        return self._cdata.nbytescomp
 
     def read(self):
-        buf = ffi.buffer(self._compdata.datacomp, self._compdata.nbytescomp)
+        buf = ffi.buffer(self._cdata.datacomp, self._cdata.nbytescomp)
         return bytes(buf)
 
     def __getattr__(self, name):
-        if hasattr(self._compdata, name):
-            return getattr(self._compdata, name)
+        if hasattr(self._cdata, name):
+            return getattr(self._cdata, name)
         raise AttributeError(name)
 
     def get_palette_pdf_string(self):
         "Returns palette pre-formatted for use in PDF"
-        buflen = len('< ') + len(' rrggbb') * self._compdata.ncolors + len('>')
-        buf = ffi.buffer(self._compdata.cmapdatahex, buflen)
+        buflen = len('< ') + len(' rrggbb') * self._cdata.ncolors + len('>')
+        buf = ffi.buffer(self._cdata.cmapdatahex, buflen)
         return bytes(buf)
 
-    @staticmethod
-    def _destroy(compdata):
-        pp = ffi.new('L_COMP_DATA **', compdata)
-        lept.l_CIDataDestroy(pp)
+
+class PixArray(LeptonicaObject, Sequence):
+    """Wrapper around PIXA (array of PIX)"""
+
+    LEPTONICA_TYPENAME = 'PIXA'
+    cdata_destroy = lept.pixaDestroy
+
+    def __len__(self):
+        return self._cdata[0].n
+
+    def __getitem__(self, n):
+        with _LeptonicaErrorTrap():
+            return Pix(lept.pixaGetPix(self._cdata, n, lept.L_CLONE))
+
+    def get_box(self, n):
+        with _LeptonicaErrorTrap():
+            return Box(lept.pixaGetBox(self._cdata, n, lept.L_CLONE))
 
 
-class Box:
-    """Wrapper around Leptonica's BOX objects.
+class Box(LeptonicaObject):
+    """Wrapper around Leptonica's BOX objects (a pixel rectangle)
 
-    See class Pix for notes about reference counting.
+    Uses x, y, w, h coordinates.
     """
 
-    def __init__(self, box):
-        self._box = ffi.gc(box, Box._box_destroy)
+    LEPTONICA_TYPENAME = 'BOX'
+    cdata_destroy = lept.boxDestroy
 
     def __repr__(self):
-        if self._box:
+        if self._cdata:
             return '<leptonica.Box x={0} y={1} w={2} h={3}>'.format(
-                self.x, self.y, self.w, self.h)
+                self.x, self.y, self.w, self.h
+            )
         return '<leptonica.Box NULL>'
 
     @property
     def x(self):
-        return self._box.x
+        return self._cdata.x
 
     @property
     def y(self):
-        return self._box.y
+        return self._cdata.y
 
     @property
     def w(self):
-        return self._box.w
+        return self._cdata.w
 
     @property
     def h(self):
-        return self._box.h
+        return self._cdata.h
 
-    @staticmethod
-    def _box_destroy(box):
-        p_box = ffi.new('BOX **', box)
-        lept.boxDestroy(p_box)
+
+class BoxArray(LeptonicaObject, Sequence):
+    """Wrapper around Leptonica's BOXA (Array of BOX) objects."""
+
+    LEPTONICA_TYPENAME = 'BOXA'
+    cdata_destroy = lept.boxaDestroy
+
+    def __repr__(self):
+        if not self._cdata:
+            return '<BoxArray>'
+        boxes = (repr(box) for box in self)
+        return '<BoxArray [' + ', '.join(boxes) + ']>'
+
+    def __len__(self):
+        return self._cdata.n
+
+    def __getitem__(self, n):
+        if not isinstance(n, int):
+            raise TypeError('list indices must be integers')
+        if 0 <= n < len(self):
+            return Box(lept.boxaGetBox(self._cdata, n, lept.L_CLONE))
+        raise IndexError(n)
+
+
+class StringArray(LeptonicaObject, Sequence):
+    """Leptonica SARRAY/string array"""
+
+    LEPTONICA_TYPENAME = 'SARRAY'
+    cdata_destroy = lept.sarrayDestroy
+
+    def __len__(self):
+        return self._cdata.n
+
+    def __getitem__(self, n):
+        if 0 <= n < len(self):
+            return ffi.string(self._cdata.array[n])
+        raise IndexError(n)
+
+
+class Sel(LeptonicaObject):
+    """Leptonica 'sel'/selection element for hit-miss transform"""
+
+    LEPTONICA_TYPENAME = 'SEL'
+    cdata_destroy = lept.selDestroy
+
+    @classmethod
+    def from_selstr(cls, selstr, name):
+        # TODO this will strip a horizontal line of don't care's
+        lines = [line.strip() for line in selstr.split('\n') if line.strip()]
+        h = len(lines)
+        w = len(lines[0])
+        lengths = set(len(line) for line in lines)
+        if len(lengths) != 1:
+            raise ValueError("All lines in selstr must be same length")
+
+        repacked = ''.join(line.strip() for line in lines)
+        buf_selstr = ffi.from_buffer(repacked.encode('ascii'))
+        buf_name = ffi.from_buffer(name.encode('ascii'))
+        sel = lept.selCreateFromString(buf_selstr, h, w, buf_name)
+        return cls(sel)
+
+    @classmethod
+    def create_brick(cls, h, w, cy, cx, type_):
+        sel = lept.selCreateBrick(h, w, cy, cx, type_)
+        return cls(sel)
+
+    def __repr__(self):
+        selstr = ffi.gc(lept.selPrintToString(self._cdata), lept.lept_free)
+        return '<Sel \n' + ffi.string(selstr).decode('ascii') + '\n>'
 
 
 @lru_cache(maxsize=1)
@@ -612,15 +845,22 @@ def deskew(infile, outfile, dpi):
         raise LeptonicaIOError("Failed to open destination file: %s" % outfile)
 
 
-def remove_background(infile, outfile, tile_size=(40, 60), gamma=1.0,
-                      black_threshold=70, white_threshold=190):
+def remove_background(
+    infile,
+    outfile,
+    tile_size=(40, 60),
+    gamma=1.0,
+    black_threshold=70,
+    white_threshold=190,
+):
     try:
         pix = Pix.open(infile)
     except LeptonicaIOError:
         raise LeptonicaIOError("Failed to open file: %s" % infile)
 
     pix = pix.background_norm(tile_size=tile_size).gamma_trc(
-            gamma, black_threshold, white_threshold)
+        gamma, black_threshold, white_threshold
+    )
 
     try:
         pix.write_implied_format(outfile)
@@ -629,15 +869,22 @@ def remove_background(infile, outfile, tile_size=(40, 60), gamma=1.0,
 
 
 if __name__ == '__main__':
-    parser = argparse.ArgumentParser(
-        description="Python wrapper to access Leptonica")
+    parser = argparse.ArgumentParser(description="Python wrapper to access Leptonica")
 
-    subparsers = parser.add_subparsers(title='commands',
-                                       description='supported operations')
+    subparsers = parser.add_subparsers(
+        title='commands', description='supported operations'
+    )
 
     parser_deskew = subparsers.add_parser('deskew')
-    parser_deskew.add_argument('-r', '--dpi', dest='dpi', action='store',
-                               type=int, default=300, help='input resolution')
+    parser_deskew.add_argument(
+        '-r',
+        '--dpi',
+        dest='dpi',
+        action='store',
+        type=int,
+        default=300,
+        help='input resolution',
+    )
     parser_deskew.add_argument('infile', help='image to deskew')
     parser_deskew.add_argument('outfile', help='deskewed output image')
     parser_deskew.set_defaults(func=deskew)

src/ocrmypdf/lib/compile_leptonica.py

@@ -19,8 +19,8 @@
 from cffi import FFI
 
 ffibuilder = FFI()
-ffibuilder.set_source("ocrmypdf.lib._leptonica", None)
-ffibuilder.cdef("""
+ffibuilder.cdef(
+    """
 typedef signed char             l_int8;
 typedef unsigned char           l_uint8;
 typedef short                   l_int16;
@@ -32,6 +32,8 @@ typedef double                  l_float64;
 typedef long long               l_int64;
 typedef unsigned long long      l_uint64;
 
+typedef int l_ok; /*!< return type 0 if OK, 1 on error */
+
 struct Pix
 {
     l_uint32             w;           /* width in pixels                   */
@@ -61,6 +63,17 @@ struct PixColormap
 };
 typedef struct PixColormap  PIXCMAP;
 
+/*! Array of pix */
+struct Pixa
+{
+    l_int32             n;          /*!< number of Pix in ptr array        */
+    l_int32             nalloc;     /*!< number of Pix ptrs allocated      */
+    l_uint32            refcount;   /*!< reference count (1 if no clones)  */
+    struct Pix        **pix;        /*!< the array of ptrs to pix          */
+    struct Boxa        *boxa;       /*!< array of boxes                    */
+};
+typedef struct Pixa PIXA;
+
 struct Box
 {
     l_int32            x;
@@ -72,6 +85,25 @@ struct Box
 };
 typedef struct Box    BOX;
 
+/*! Array of Box */
+struct Boxa
+{
+    l_int32            n;           /*!< number of box in ptr array        */
+    l_int32            nalloc;      /*!< number of box ptrs allocated      */
+    l_uint32           refcount;    /*!< reference count (1 if no clones)  */
+    struct Box       **box;         /*!< box ptr array                     */
+};
+typedef struct Boxa BOXA;
+
+/*! String array: an array of C strings */
+struct Sarray
+{
+    l_int32          nalloc;    /*!< size of allocated ptr array         */
+    l_int32          n;         /*!< number of strings allocated         */
+    l_int32          refcount;  /*!< reference count (1 if no clones)    */
+    char           **array;     /*!< string array                        */
+};
+typedef struct Sarray SARRAY;
 
 /*! Pdf formatted encoding types */
 enum {
@@ -104,6 +136,18 @@ struct L_Compressed_Data
 };
 typedef struct L_Compressed_Data L_COMP_DATA;
 
+/*! Selection */
+struct Sel
+{
+    l_int32       sy;        /*!< sel height                               */
+    l_int32       sx;        /*!< sel width                                */
+    l_int32       cy;        /*!< y location of sel origin                 */
+    l_int32       cx;        /*!< x location of sel origin                 */
+    l_int32     **data;      /*!< {0,1,2}; data[i][j] in [row][col] order  */
+    char         *name;      /*!< used to find sel by name                 */
+};
+typedef struct Sel SEL;
+
 enum {
     REMOVE_CMAP_TO_BINARY = 0,     /*!< remove colormap for conv to 1 bpp  */
     REMOVE_CMAP_TO_GRAYSCALE = 1,  /*!< remove colormap for conv to 8 bpp  */
@@ -122,10 +166,50 @@ enum {
                       /*!< the array with clones (e.g., pix)              */
 };
 
-""")
+/*! Flags for method of extracting barcode widths */
+enum {
+    L_USE_WIDTHS = 1,     /*!< use histogram of barcode widths           */
+    L_USE_WINDOWS = 2     /*!< find best window for decoding transitions */
+};
 
-ffibuilder.cdef("""
+/*! Flags for barcode formats */
+enum {
+    L_BF_UNKNOWN = 0,     /*!< unknown format                            */
+    L_BF_ANY = 1,         /*!< try decoding with all known formats       */
+    L_BF_CODE128 = 2,     /*!< decode with Code128 format                */
+    L_BF_EAN8 = 3,        /*!< decode with EAN8 format                   */
+    L_BF_EAN13 = 4,       /*!< decode with EAN13 format                  */
+    L_BF_CODE2OF5 = 5,    /*!< decode with Code 2 of 5 format            */
+    L_BF_CODEI2OF5 = 6,   /*!< decode with Interleaved 2 of 5 format     */
+    L_BF_CODE39 = 7,      /*!< decode with Code39 format                 */
+    L_BF_CODE93 = 8,      /*!< decode with Code93 format                 */
+    L_BF_CODABAR = 9,     /*!< decode with Code93 format                 */
+    L_BF_UPCA = 10        /*!< decode with UPC A format                  */
+};
+
+enum {
+    L_SEVERITY_EXTERNAL = 0,   /* Get the severity from the environment   */
+    L_SEVERITY_ALL      = 1,   /* Lowest severity: print all messages     */
+    L_SEVERITY_DEBUG    = 2,   /* Print debugging and higher messages     */
+    L_SEVERITY_INFO     = 3,   /* Print informational and higher messages */
+    L_SEVERITY_WARNING  = 4,   /* Print warning and higher messages       */
+    L_SEVERITY_ERROR    = 5,   /* Print error and higher messages         */
+    L_SEVERITY_NONE     = 6    /* Highest severity: print no messages     */
+};
+
+enum {
+    SEL_DONT_CARE  = 0,
+    SEL_HIT        = 1,
+    SEL_MISS       = 2
+};
+
+"""
+)
+
+ffibuilder.cdef(
+    """
 PIX * pixRead ( const char *filename );
+PIX * pixReadMem ( const l_uint8 *data, size_t size );
 PIX * pixScale ( PIX *pixs, l_float32 scalex, l_float32 scaley );
 l_int32 pixFindSkew ( PIX *pixs, l_float32 *pangle, l_float32 *pconf );
 l_int32 pixWriteImpliedFormat ( const char *filename, PIX *pix, l_int32 quality, l_int32 progressive );
@@ -137,6 +221,11 @@ pixWriteMemPng(l_uint8  **pdata,
 
 void pixDestroy ( PIX **ppix );
 
+l_ok
+pixEqual(PIX      *pix1,
+         PIX      *pix2,
+         l_int32 *psame);
+
 PIX *
 pixEndianByteSwapNew(PIX  *pixs);
 
@@ -157,6 +246,8 @@ l_int32 pixSerializeToMemory ( PIX *pixs, l_uint32 **pdata, size_t *pnbytes );
 
 PIX * pixConvertRGBToLuminance(PIX *pixs);
 
+PIX * pixConvertTo8(PIX     *pixs, l_int32  cmapflag);
+
 PIX * pixRemoveColormap(PIX *pixs, l_int32  type);
 
 l_int32
@@ -182,6 +273,18 @@ pixOtsuThreshOnBackgroundNorm(PIX       *pixs,
                               l_float32  scorefract,
                               l_int32   *pthresh);
 
+PIX *
+pixMaskedThreshOnBackgroundNorm(PIX       *pixs,
+                                PIX       *pixim,
+                                l_int32    sx,
+                                l_int32    sy,
+                                l_int32    thresh,
+                                l_int32    mincount,
+                                l_int32    smoothx,
+                                l_int32    smoothy,
+                                l_float32  scorefract,
+                                l_int32   *pthresh);
+
 PIX *
 pixCleanBackgroundToWhite(PIX       *pixs,
                           PIX       *pixim,
@@ -265,13 +368,13 @@ pixGetAverageMaskedRGB(PIX        *pixs,
                        l_float32  *pgval,
                        l_float32  *pbval);
 
-PIX * 
+PIX *
 pixGlobalNormRGB(PIX * 	pixd,
                  PIX * 	pixs,
                  l_int32 	rval,
                  l_int32 	gval,
                  l_int32 	bval,
-                 l_int32 	mapval); 
+                 l_int32 	mapval);
 
 PIX *
 pixInvert(PIX * pixd,
@@ -289,22 +392,102 @@ pixGenerateCIData(PIX           *pixs,
                   l_int32        ascii85,
                   L_COMP_DATA **pcid);
 
-l_int32 
-l_generateCIDataForPdf(const char *fname, 
-                       PIX *pix, 
-                       l_int32 quality, 
+SARRAY *
+pixProcessBarcodes(PIX      *pixs,
+                   l_int32   format,
+                   l_int32   method,
+                   SARRAY  **psaw,
+                   l_int32 debugflag);
+
+PIX *
+pixaGetPix(PIXA    *pixa,
+           l_int32  index,
+           l_int32 accesstype);
+
+BOX*
+pixaGetBox 	(PIXA *  	pixa,
+		    l_int32  	index,
+		    l_int32  	accesstype );
+
+PIXA *
+pixExtractBarcodes(PIX     *pixs,
+                   l_int32 debugflag);
+
+BOXA *
+pixLocateBarcodes ( PIX *pixs, l_int32 thresh, PIX **ppixb, PIX **ppixm );
+
+SARRAY *
+pixReadBarcodes(PIXA     *pixa,
+                l_int32   format,
+                l_int32   method,
+                SARRAY  **psaw,
+                l_int32 debugflag);
+
+l_int32
+l_generateCIDataForPdf(const char *fname,
+                       PIX *pix,
+                       l_int32 quality,
                        L_COMP_DATA **pcid);
 
-void                 
+
+BOX *
+boxClone ( BOX *box );
+
+BOX *
+boxaGetBox ( BOXA *boxa, l_int32 index, l_int32 accessflag );
+
+SEL *
+selCreateFromString ( const char *text, l_int32 h, l_int32 w, const char *name );
+
+SEL *
+selCreateBrick ( l_int32 h, l_int32 w, l_int32 cy, l_int32 cx, l_int32 type );
+
+char *
+selPrintToString(SEL  *sel);
+
+PIX *
+pixDilate ( PIX *pixd, PIX *pixs, SEL *sel );
+
+PIX *
+pixErode ( PIX *pixd, PIX *pixs, SEL *sel );
+
+PIX *
+pixHMT ( PIX *pixd, PIX *pixs, SEL *sel );
+
+PIX *
+pixSubtract ( PIX *pixd, PIX *pixs1, PIX *pixs2 );
+
+void
 boxDestroy(BOX  **pbox);
 
+void
+boxaDestroy ( BOXA **pboxa );
+
+void
+pixaDestroy(PIXA **ppixa);
+
+l_ok
+pixRenderBoxa ( PIX *pix, BOXA *boxa, l_int32 width, l_int32 op );
+
 void
 l_CIDataDestroy(L_COMP_DATA **pcid);
 
 void
-lept_free(void *ptr);  
-""")
+sarrayDestroy(SARRAY  **psa);
 
+void
+lept_free(void *ptr);
+
+void selDestroy ( SEL **psel );
+
+l_int32
+setMsgSeverity(l_int32 newsev);
+
+"""
+)
+
+
+ffibuilder.set_source("ocrmypdf.lib._leptonica", None)
 
 if __name__ == '__main__':
     ffibuilder.compile(verbose=True)

src/ocrmypdf/optimize.py

@@ -15,33 +15,28 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from pathlib import Path
 import concurrent.futures
-from collections import defaultdict, namedtuple
 import logging
 import sys
+from collections import defaultdict
+from os import fspath
+from pathlib import Path
 
 from PIL import Image
 
 import pikepdf
-try:
-    from pikepdf import Null  # pikepdf <= 0.2.2
-except ImportError:
-    def Null():               # pikepdf > 0.2.2
-        return None
 
-from ._jobcontext import JobContext
 from . import leptonica
-from .helpers import re_symlink, fspath
-from .exec import pngquant, jbig2enc
+from ._jobcontext import JobContext
+from .exec import jbig2enc, pngquant
+from .helpers import re_symlink
 
-PAGE_GROUP_SIZE = 10
 DEFAULT_JPEG_QUALITY = 75
-DEFAULT_PNG_QUALITY = (65, 75)
+DEFAULT_PNG_QUALITY = 70
 
 
 def img_name(root, xref, ext):
-    return fspath(root / '{:08d}{}'.format(xref, ext))
+    return fspath(root / f'{xref:08d}{ext}')
 
 
 def png_name(root, xref):
@@ -56,40 +51,58 @@ def tif_name(root, xref):
     return img_name(root, xref, '.tif')
 
 
-def extract_image(*, pike, root, log, image, xref, jbig2s,
-                  pngs, jpegs, options):
+def extract_image_filter(pike, root, log, image, xref):
     if image.Subtype != '/Image':
-        return False
+        return None
     if image.Length < 100:
-        log.debug("Skipping small image, xref {}".format(xref))
-        return False
+        log.debug("Skipping small image, xref %s", xref)
+        return None
 
     pim = pikepdf.PdfImage(image)
 
     if len(pim.filter_decodeparms) > 1:
-        log.debug("Skipping multiply filtered, xref {}".format(xref))
-        return False
+        log.debug("Skipping multiply filtered, xref %s", xref)
+        return None
     filtdp = pim.filter_decodeparms[0]
 
     if pim.bits_per_component > 8:
-        return False  # Don't mess with wide gamut images
+        return None  # Don't mess with wide gamut images
 
     if filtdp[0] == '/JPXDecode':
-        return False  # Don't do JPEG2000
+        return None  # Don't do JPEG2000
 
-    if pim.bits_per_component == 1 \
-            and filtdp != '/JBIG2Decode' \
-            and jbig2enc.available():
+    return pim, filtdp
+
+
+def extract_image_jbig2(*, pike, root, log, image, xref, options):
+    result = extract_image_filter(pike, root, log, image, xref)
+    if result is None:
+        return None
+    pim, filtdp = result
+
+    if (
+        pim.bits_per_component == 1
+        and filtdp != '/JBIG2Decode'
+        and jbig2enc.available()
+    ):
         try:
-            imgname = Path(root / '{:08d}'.format(xref))
+            imgname = Path(root / f'{xref:08d}')
             with imgname.open('wb') as f:
                 ext = pim.extract_to(stream=f)
             imgname.rename(imgname.with_suffix(ext))
         except pikepdf.UnsupportedImageTypeError:
-            return False
-        jbig2s.append((xref, ext))
-    elif filtdp[0] == '/DCTDecode' \
-            and options.optimize >= 2:
+            return None
+        return xref, ext
+    return None
+
+
+def extract_image_generic(*, pike, root, log, image, xref, options):
+    result = extract_image_filter(pike, root, log, image, xref)
+    if result is None:
+        return None
+    pim, filtdp = result
+
+    if filtdp[0] == '/DCTDecode' and options.optimize >= 2:
         # This is a simple heuristic derived from some training data, that has
         # about a 70% chance of guessing whether the JPEG is high quality,
         # and possibly recompressible, or not. The number itself doesn't mean
@@ -97,7 +110,7 @@ def extract_image(*, pike, root, log, image, xref, jbig2s,
         # bytes_per_pixel = int(raw_jpeg.Length) / (w * h)
         # jpeg_quality_estimate = 117.0 * (bytes_per_pixel ** 0.213)
         # if jpeg_quality_estimate < 65:
-        #     return False
+        #     return None
 
         # We could get the ICC profile here, but there's no need to look at it
         # for quality transcoding
@@ -107,120 +120,182 @@ def extract_image(*, pike, root, log, image, xref, jbig2s,
         #     with Image.open(stream) as im:
         #         im.save(jpg_name(root, xref), icc_profile=iccbytes)
         try:
-            imgname = Path(root / '{:08d}'.format(xref))
+            imgname = Path(root / f'{xref:08d}')
             with imgname.open('wb') as f:
                 ext = pim.extract_to(stream=f)
             imgname.rename(imgname.with_suffix(ext))
         except pikepdf.UnsupportedImageTypeError:
-            return False
-        jpegs.append(xref)
-    elif pim.indexed \
-            and pim.colorspace in pim.SIMPLE_COLORSPACES \
-            and options.optimize >= 3:
+            return None
+        return xref, ext
+    elif (
+        pim.indexed
+        and pim.colorspace in pim.SIMPLE_COLORSPACES
+        and options.optimize >= 3
+    ):
         # Try to improve on indexed images - these are far from low hanging
         # fruit in most cases
         pim.as_pil_image().save(png_name(root, xref))
-        pngs.append(xref)
+        return xref, '.png'
     elif not pim.indexed and pim.colorspace in pim.SIMPLE_COLORSPACES:
         # An optimization opportunity here, not currently taken, is directly
         # generating a PNG from compressed data
         pim.as_pil_image().save(png_name(root, xref))
-        pngs.append(xref)
-    else:
-        return False
+        return xref, '.png'
 
-    return True
+    return None
 
 
-def extract_images(pike, root, log, options):
-    # Extract images we can improve
-    changed_xrefs = set()
-    jbig2_groups = defaultdict(lambda: [])
-    jpegs = []
-    pngs = []
+def extract_images(pike, root, log, options, extract_fn):
+    """Extract image using extract_fn
+
+    extract_fn decides whether the image is interesting in this case
+    """
+
+    include_xrefs = set()
+    exclude_xrefs = set()
     errors = 0
     for pageno, page in enumerate(pike.pages):
-        group, _ = divmod(pageno, PAGE_GROUP_SIZE)
         try:
             xobjs = page.Resources.XObject
         except AttributeError:
             continue
-        for imname, image in dict(xobjs).items():
+        for _imname, image in dict(xobjs).items():
             if image.objgen[1] != 0:
                 continue  # Ignore images in an incremental PDF
             xref = image.objgen[0]
-            if xref in changed_xrefs:
-                continue  # Don't improve same image twice
-            try:
-                result = extract_image(
-                    pike=pike, root=root, log=log, image=image,
-                    xref=xref, jbig2s=jbig2_groups[group], pngs=pngs,
-                    jpegs=jpegs, options=options
-                )
-                if result:
-                    changed_xrefs.add(xref)
-            except Exception as e:
-                log.debug("Image {} xref {}".format(imname, xref))
-                log.debug(repr(e))
-                errors += 1
+            if hasattr(image, 'SMask'):
+                # Ignore soft masks
+                smask_xref = image.SMask.objgen[0]
+                exclude_xrefs.add(smask_xref)
+            include_xrefs.add(xref)
+
+    working_xrefs = include_xrefs - exclude_xrefs
+    for xref in working_xrefs:
+        image = pike.get_object((xref, 0))
+        try:
+            result = extract_fn(
+                pike=pike, root=root, log=log, image=image, xref=xref, options=options
+            )
+        except Exception as e:
+            log.debug("Image xref %s", xref)
+            log.debug(repr(e))
+            errors += 1
+        else:
+            if result:
+                _, ext = result
+                yield pageno, xref, ext
+
+
+def extract_images_generic(pike, root, log, options):
+    """Extract any >=2bpp image we think we can improve"""
+
+    jpegs = []
+    pngs = []
+    for _, xref, ext in extract_images(pike, root, log, options, extract_image_generic):
+        log.debug('xref = %s ext = %s', xref, ext)
+        if ext == '.png':
+            pngs.append(xref)
+        elif ext == '.jpg':
+            jpegs.append(xref)
+    log.debug("Optimizable images: " "JPEGs: %s PNGs: %s", len(jpegs), len(pngs))
+    return jpegs, pngs
+
+
+def extract_images_jbig2(pike, root, log, options):
+    """Extract any bitonal image that we think we can improve as JBIG2"""
+
+    jbig2_groups = defaultdict(list)
+    for pageno, xref, ext in extract_images(
+        pike, root, log, options, extract_image_jbig2
+    ):
+        group = pageno // options.jbig2_page_group_size
+        jbig2_groups[group].append((xref, ext))
 
     # Elide empty groups
-    jbig2_groups = {group: xrefs for group, xrefs in jbig2_groups.items()
-                    if len(xrefs) > 0}
-    log.debug(
-        "Optimizable images: "
-        "JBIG2 groups: {} JPEGs: {} PNGs: {} Errors: {}".format(
-            len(jbig2_groups), len(jpegs), len(pngs), errors
-    ))
-
-    return jbig2_groups, jpegs, pngs
+    jbig2_groups = {
+        group: xrefs for group, xrefs in jbig2_groups.items() if len(xrefs) > 0
+    }
+    log.debug("Optimizable images: " "JBIG2 groups: %s", (len(jbig2_groups),))
+    return jbig2_groups
 
 
-def convert_to_jbig2(pike, jbig2_groups, root, log, options):
-    """
-    Convert a group of JBIG2 images and insert into PDF.
+def _produce_jbig2_images(jbig2_groups, root, log, options):
+    """Produce JBIG2 images from their groups"""
 
-    We use a group because JBIG2 works best with a symbol dictionary that spans
-    multiple pages. When inserted back into the PDF, each JBIG2 must reference
-    the symbol dictionary it is associated with. So convert a group at a time,
-    and replace their streams with a parameter set that points to the
-    appropriate dictionary.
-
-    If too many pages shared the same dictionary JBIG2 encoding becomes more
-    expensive and less efficient.
-
-    """
-    with concurrent.futures.ThreadPoolExecutor(
-            max_workers=options.jobs) as executor:
-        futures = []
-        for group, xref_exts in jbig2_groups.items():
-            prefix = 'group{:08d}'.format(group)
+    def jbig2_group_futures(executor, root, groups):
+        for group, xref_exts in groups.items():
+            prefix = f'group{group:08d}'
             future = executor.submit(
                 jbig2enc.convert_group,
                 cwd=fspath(root),
                 infiles=(img_name(root, xref, ext) for xref, ext in xref_exts),
-                out_prefix=prefix
+                out_prefix=prefix,
             )
-            futures.append(future)
+            yield future
+
+    def jbig2_single_futures(executor, root, groups):
+        for group, xref_exts in groups.items():
+            prefix = f'group{group:08d}'
+            # Second loop is to ensure multiple images per page are unpacked
+            for n, xref_ext in enumerate(xref_exts):
+                xref, ext = xref_ext
+                future = executor.submit(
+                    jbig2enc.convert_single,
+                    cwd=fspath(root),
+                    infile=img_name(root, xref, ext),
+                    outfile=root / f'{prefix}.{n:04d}',
+                )
+                yield future
+
+    if options.jbig2_page_group_size > 1:
+        jbig2_futures = jbig2_group_futures
+    else:
+        jbig2_futures = jbig2_single_futures
+
+    with concurrent.futures.ThreadPoolExecutor(max_workers=options.jobs) as executor:
+        futures = jbig2_futures(executor, root, jbig2_groups)
         for future in concurrent.futures.as_completed(futures):
             proc = future.result()
             log.debug(proc.stderr.decode())
 
+
+def convert_to_jbig2(pike, jbig2_groups, root, log, options):
+    """Convert images to JBIG2 and insert into PDF.
+
+    When the JBIG2 page group size is > 1 we do several JBIG2 images at once
+    and build a symbol dictionary that will span several pages. Each JBIG2
+    image must reference to its symbol dictionary. If too many pages shared the
+    same dictionary JBIG2 encoding becomes more expensive and less efficient.
+    The default value of 10 was determined through testing. Currently this
+    must be lossy encoding since jbig2enc does not support refinement coding.
+
+    When the JBIG2 symbolic coder is not used, each JBIG2 stands on its own
+    and needs no dictionary. Currently this is must be lossless JBIG2.
+    """
+
+    _produce_jbig2_images(jbig2_groups, root, log, options)
+
     for group, xref_exts in jbig2_groups.items():
-        prefix = 'group{:08d}'.format(group)
-        jbig2_globals_data = (root / (prefix + '.sym')).read_bytes()
-        jbig2_globals = pikepdf.Stream(pike, jbig2_globals_data)
+        prefix = f'group{group:08d}'
+        jbig2_symfile = root / (prefix + '.sym')
+        if jbig2_symfile.exists():
+            jbig2_globals_data = jbig2_symfile.read_bytes()
+            jbig2_globals = pikepdf.Stream(pike, jbig2_globals_data)
+            jbig2_globals_dict = pikepdf.Dictionary({'/JBIG2Globals': jbig2_globals})
+        elif options.jbig2_page_group_size == 1:
+            jbig2_globals_dict = None
+        else:
+            raise FileNotFoundError(jbig2_symfile)
 
         for n, xref_ext in enumerate(xref_exts):
             xref, _ = xref_ext
-            jbig2_im_file = root / (prefix + '.{:04d}'.format(n))
+            jbig2_im_file = root / (prefix + f'.{n:04d}')
             jbig2_im_data = jbig2_im_file.read_bytes()
             im_obj = pike.get_object(xref, 0)
             im_obj.write(
-                jbig2_im_data, pikepdf.Name('/JBIG2Decode'),
-                pikepdf.Dictionary({
-                    '/JBIG2Globals': jbig2_globals
-                })
+                jbig2_im_data,
+                filter=pikepdf.Name('/JBIG2Decode'),
+                decode_parms=jbig2_globals_dict,
             )
 
 
@@ -234,35 +309,34 @@ def transcode_jpegs(pike, jpegs, root, log, options):
         # 'close'.  Seems to be mostly harmless
         # https://github.com/python-pillow/Pillow/issues/1144
         with Image.open(fspath(in_jpg)) as im:
-            im.save(fspath(opt_jpg),
-                    optimize=True,
-                    quality=options.jpeg_quality)
-        # pylint: disable=E1101
+            im.save(fspath(opt_jpg), optimize=True, quality=options.jpeg_quality)
+        # pylint: disable=no-member
         if opt_jpg.stat().st_size > in_jpg.stat().st_size:
-            log.debug("xref {}, jpeg, made larger - skip".format(xref))
+            log.debug("xref %s, jpeg, made larger - skip", xref)
             continue
 
         compdata = leptonica.CompressedData.open(opt_jpg)
         im_obj = pike.get_object(xref, 0)
-        im_obj.write(
-            compdata.read(), pikepdf.Name('/DCTDecode'),
-            Null()
-        )
+        im_obj.write(compdata.read(), filter=pikepdf.Name('/DCTDecode'))
 
 
 def transcode_pngs(pike, pngs, root, log, options):
     if options.optimize >= 2:
         png_quality = (
             max(10, options.png_quality - 10),
-            min(100, options.png_quality + 10)
+            min(100, options.png_quality + 10),
         )
         with concurrent.futures.ThreadPoolExecutor(
-                max_workers=options.jobs) as executor:
+            max_workers=options.jobs
+        ) as executor:
             for xref in pngs:
                 executor.submit(
                     pngquant.quantize,
-                    png_name(root, xref), png_name(root, xref),
-                    png_quality[0], png_quality[1])
+                    png_name(root, xref),
+                    png_name(root, xref),
+                    png_quality[0],
+                    png_quality[1],
+                )
 
     for xref in pngs:
         im_obj = pike.get_object(xref, 0)
@@ -272,9 +346,7 @@ def transcode_pngs(pike, pngs, root, log, options):
             pix = leptonica.Pix.open(png_name(root, xref))
             if pix.depth == 1:
                 pix = pix.invert()  # PDF assumes 1 is black for monochrome
-            compdata = pix.generate_pdf_ci_data(
-                leptonica.lept.L_FLATE_ENCODE, 0
-            )
+            compdata = pix.generate_pdf_ci_data(leptonica.lept.L_FLATE_ENCODE, 0)
         except leptonica.LeptonicaError as e:
             log.error(e)
             continue
@@ -282,11 +354,11 @@ def transcode_pngs(pike, pngs, root, log, options):
         # This is what we should be doing: open the compressed data without
         # transcoding. However this shifts each pixel row by one for some
         # reason.
-        #compdata = leptonica.CompressedData.open(png_name(root, xref))
+        # compdata = leptonica.CompressedData.open(png_name(root, xref))
         if len(compdata) > int(im_obj.stream_dict.Length):
             continue  # If we produced a larger image, don't use
 
-        predictor = Null()
+        predictor = None
         if compdata.predictor > 0:
             predictor = pikepdf.Dictionary({'/Predictor': compdata.predictor})
 
@@ -298,8 +370,12 @@ def transcode_pngs(pike, pngs, root, log, options):
             palette_pdf_string = compdata.get_palette_pdf_string()
             palette_data = pikepdf.Object.parse(palette_pdf_string)
             palette_stream = pikepdf.Stream(pike, bytes(palette_data))
-            palette = [pikepdf.Name('/Indexed'), pikepdf.Name('/DeviceRGB'),
-                       compdata.ncolors - 1, palette_stream]
+            palette = [
+                pikepdf.Name('/Indexed'),
+                pikepdf.Name('/DeviceRGB'),
+                compdata.ncolors - 1,
+                palette_stream,
+            ]
             cs = palette
         else:
             if compdata.spp == 1:
@@ -309,14 +385,12 @@ def transcode_pngs(pike, pngs, root, log, options):
             elif compdata.spp == 4:
                 cs = pikepdf.Name('/DeviceCMYK')
         im_obj.ColorSpace = cs
-        im_obj.write(compdata.read(), pikepdf.Name('/FlateDecode'), predictor)
+        im_obj.write(
+            compdata.read(), filter=pikepdf.Name('/FlateDecode'), decode_parms=predictor
+        )
 
 
-def optimize(
-    input_file,
-    output_file,
-    log,
-    context):
+def optimize(input_file, output_file, log, context):
 
     options = context.get_options()
     if options.optimize == 0:
@@ -324,33 +398,37 @@ def optimize(
         return
 
     if options.jpeg_quality == 0:
-        options.jpeg_quality = \
-                DEFAULT_JPEG_QUALITY if options.optimize < 3 else 40
+        options.jpeg_quality = DEFAULT_JPEG_QUALITY if options.optimize < 3 else 40
     if options.png_quality == 0:
-        options.png_quality = \
-                DEFAULT_PNG_QUALITY if options.optimize < 3 else 30
+        options.png_quality = DEFAULT_PNG_QUALITY if options.optimize < 3 else 30
+    if options.jbig2_page_group_size == 0:
+        options.jbig2_page_group_size = 10 if options.jbig2_lossy else 1
 
     pike = pikepdf.Pdf.open(input_file)
 
     root = Path(output_file).parent / 'images'
-    root.mkdir(exist_ok=True)  # pylint: disable=E1101
-    jbig2_groups, jpegs, pngs = extract_images(
-        pike, root, log, options)
+    root.mkdir(exist_ok=True)  # pylint: disable=no-member
 
-    convert_to_jbig2(pike, jbig2_groups, root, log, options)
+    jpegs, pngs = extract_images_generic(pike, root, log, options)
     transcode_jpegs(pike, jpegs, root, log, options)
     transcode_pngs(pike, pngs, root, log, options)
 
-    # Not object_stream_mode + preserve_pdfa generates noncompliant PDFs
+    jbig2_groups = extract_images_jbig2(pike, root, log, options)
+    convert_to_jbig2(pike, jbig2_groups, root, log, options)
+
     target_file = Path(output_file).with_suffix('.opt.pdf')
-    pike.save(target_file, preserve_pdfa=True)
+    pike.remove_unreferenced_resources()
+    pike.save(
+        target_file,
+        preserve_pdfa=True,
+        object_stream_mode=pikepdf.ObjectStreamMode.generate,
+    )
 
     input_size = Path(input_file).stat().st_size
     output_size = Path(target_file).stat().st_size
     ratio = input_size / output_size
     savings = 1 - output_size / input_size
-    log.info("Optimize ratio: {:.2f} savings: {:.1f}%".format(
-        ratio, 100 * savings))
+    log.info(f"Optimize ratio: {ratio:.2f} savings: {(100 * savings):.1f}%")
 
     if savings < 0:
         log.info("Optimize did not improve the file - discarded")
@@ -366,11 +444,13 @@ def main(infile, outfile, level, jobs=1):
     class OptimizeOptions:
         """Emulate ocrmypdf's options"""
 
-        def __init__(self, jobs, optimize, jpeg_quality, png_quality):
+        def __init__(self, jobs, optimize, jpeg_quality, png_quality, jb2lossy):
             self.jobs = jobs
             self.optimize = optimize
             self.jpeg_quality = jpeg_quality
             self.png_quality = png_quality
+            self.jbig2_page_group_size = 0
+            self.jbig2_lossy = jb2lossy
 
     logging.basicConfig(level=logging.DEBUG)
     log = logging.getLogger()
@@ -380,7 +460,8 @@ def main(infile, outfile, level, jobs=1):
         jobs=jobs,
         optimize=int(level),
         jpeg_quality=0,  # Use default
-        png_quality=0
+        png_quality=0,
+        jb2lossy=False,
     )
     ctx.set_options(options)
 

src/ocrmypdf/pdfa.py

@@ -15,25 +15,34 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-# Generate a PDFA_def.ps file for Ghostscript >= 9.14
+"""
+Generate a PDFMARK file for Ghostscript >= 9.14, for PDF/A conversion
+
+pdfmark is an extension to the Postscript language that describes some PDF
+features like bookmarks and annotations. It was originally specified Adobe
+Distiller, for Postscript to PDF conversion:
+https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/pdfmark_reference.pdf
+
+Ghostscript uses pdfmark for PDF to PDF/A conversion as well. To use Ghostscript
+to create a PDF/A, we need to create a pdfmark file with the necessary metadata.
+
+This takes care of the many version-specific bugs and pecularities in
+Ghostscript's handling of pdfmark.
+
+"""
 
-from binascii import hexlify
-from datetime import datetime
-from pathlib import Path
-from shutil import copyfile
-from string import Template
-import pkg_resources
 import os
+from binascii import hexlify
+from pathlib import Path
+from string import Template
 
-from libxmp.utils import file_to_dict
-from libxmp import consts
+import pkg_resources
 
-from ocrmypdf.helpers import fspath
+import pikepdf
 
 ICC_PROFILE_RELPATH = 'data/sRGB.icc'
 
-SRGB_ICC_PROFILE = pkg_resources.resource_filename(
-    'ocrmypdf', ICC_PROFILE_RELPATH)
+SRGB_ICC_PROFILE = pkg_resources.resource_filename('ocrmypdf', ICC_PROFILE_RELPATH)
 
 
 # This is a template written in PostScript which is needed to create PDF/A
@@ -44,9 +53,6 @@ pdfa_def_template = u"""%!
 /ICCProfile $icc_profile
 def
 
-[$docinfo
-  /DOCINFO pdfmark
-
 % Define an ICC profile :
 
 [/_objdef {icc_PDFA} /type /stream /OBJ pdfmark
@@ -77,152 +83,29 @@ def
 """
 
 
-def encode_text_string(s: str) -> str:
-    '''Encode text string to hex string for use in a PDF
+def generate_pdfa_ps(target_filename, icc='sRGB'):
+    """Create a Postscript pdfmark file for Ghostscript PDF/A conversion
 
-    From PDF 32000-1:2008 a string object may be included in hexademical form
-    if it is enclosed in angle brackets.  For general Unicode the string should
-    be UTF-16 (big endian) with byte order marks.  Many strings including all
-    ASCII strings could be encoded as PdfDocEncoding literals provided
-    that certain Postscript sequences are escaped.  But it's far simpler to
-    encode everything as UTF-16.
-    '''
+    A pdfmark file is a small Postscript program that provides some information
+    Ghostscript needs to perform PDF/A conversion. The only information we put
+    in specifies that we want the file to be a PDF/A, and we want to Ghostscript
+    to convert objects to the sRGB colorspace if it runs into any object that
+    it decides must be converted.
 
-    # Sometimes lazy C programmers leave their NULs at the end of strings they
-    # insert into PDFs
-    # tests/resources/aspect.pdf is one example (created by ImageMagick)
-    s = s.replace('\x00', '')
+    See the Adobe pdfmark Reference for details:
+    https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/pdfmark_reference.pdf
 
-    if s == '':
-        return ''
-
-    utf16_bytes = s.encode('utf-16be')
-    ascii_hex_bytes = hexlify(b'\xfe\xff' + utf16_bytes)
-    ascii_hex_str = ascii_hex_bytes.decode('ascii').lower()
-    return ascii_hex_str
-
-
-def encode_pdf_date(d: datetime) -> str:
-    """Encode Python datetime object as PDF date string
-
-    From Adobe pdfmark manual:
-    (D:YYYYMMDDHHmmSSOHH'mm')
-    D: is an optional prefix. YYYY is the year. All fields after the year are
-    optional. MM is the month (01-12), DD is the day (01-31), HH is the
-    hour (00-23), mm are the minutes (00-59), and SS are the seconds
-    (00-59). The remainder of the string defines the relation of local
-    time to GMT. O is either + for a positive difference (local time is
-    later than GMT) or - (minus) for a negative difference. HH' is the
-    absolute value of the offset from GMT in hours, and mm' is the
-    absolute value of the offset in minutes. If no GMT information is
-    specified, the relation between the specified time and GMT is
-    considered unknown. Regardless of whether or not GMT
-    information is specified, the remainder of the string should specify
-    the local time.
-    """
-
-    pdfmark_date_fmt = r'%Y%m%d%H%M%S'
-    s = d.strftime(pdfmark_date_fmt)
-
-    tz = d.strftime('%z')
-    if tz == 'Z' or tz == '':
-        # Ghostscript <= 9.23 handles missing timezones incorrectly, so if
-        # timezone is missing, move it into GMT.
-        # https://bugs.ghostscript.com/show_bug.cgi?id=699182
-        s += "+00'00'"
-    else:
-        sign, tz_hours, tz_mins = tz[0], tz[1:3], tz[3:5]
-        s += "{}{}'{}'".format(sign, tz_hours, tz_mins)
-    return s
-
-
-def decode_pdf_date(s: str) -> datetime:
-    if s.startswith('D:'):
-        s = s[2:]
-
-    # Literal Z00'00', is incorrect but found in the wild,
-    # probably made by OS X Quartz -- standardize
-    if s.endswith("Z00'00'"):
-        s = s.replace("Z00'00'", '+0000')
-    elif s.endswith('Z'):
-        s = s.replace('Z', '+0000')
-
-    s = s.replace("'", "")  # Remove apos from PDF time strings
-
-    return datetime.strptime(s, r'%Y%m%d%H%M%S%z')
-
-
-def _get_pdfmark_dates(pdfmark):
-    """Encode dates for pdfmark Postscript.  The best way to deal with a
-    missing date entry is set it to null, because if the key is omitted
-    Ghostscript will set it to now - we do not want to erase the fact that
-    the value was unknown.  Setting to an empty string breaks Ghostscript
-    9.22 as reported here:
-    https://bugs.ghostscript.com/show_bug.cgi?id=699182
-    """
-
-    for key in ('/CreationDate', '/ModDate'):
-        if key not in pdfmark:
-            continue
-        if pdfmark[key].strip() == '':
-            yield '  {} null'.format(key)
-            continue
-        date_str = pdfmark[key]
-        if date_str.startswith('D:'):
-            date_str = date_str[2:]
-        try:
-            yield '  {} (D:{})'.format(
-                    key,
-                    encode_pdf_date(decode_pdf_date(date_str)))
-        except ValueError:
-            yield '  {} null'.format(key)
-
-
-def _get_pdfa_def(icc_profile, icc_identifier, pdfmark):
-    """
-    Create a Postscript pdfmark file for Ghostscript.
-
-    pdfmark contains the various objects as strings; these must be encoded in
-    ASCII, and dates have a special format.
-
-    :param icc_profile: filename of the ICC profile to include in pdfmark
-    :param icc_identifier: ICC identifier such as 'sRGB'
-    :param pdfmark: a dictionary containing keys to include the pdfmark
+    :param target_filename: filename to save
+    :param icc: ICC identifier such as 'sRGB'
 
     :returns: a string containing the entire pdfmark
-
     """
-
-    # Ghostscript <= 9.21 has a bug where null entries in DOCINFO might produce
-    # ERROR: VMerror (-25) on closing pdfwrite device.
-    # https://bugs.ghostscript.com/show_bug.cgi?id=697684
-    # Work around this by only adding keys that have a nontrivial value
-    docinfo_keys = ('/Title', '/Author', '/Subject', '/Creator', '/Keywords')
-    docinfo_line_template = '  {key} <{value}>'
-
-    def docinfo_gen():
-        yield from _get_pdfmark_dates(pdfmark)
-        for key in docinfo_keys:
-            if key in pdfmark and pdfmark[key].strip() != '':
-                line = docinfo_line_template.format(
-                    key=key, value=encode_text_string(pdfmark[key]))
-                yield line
-    docinfo = '\n'.join(docinfo_gen())
-
-    t = Template(pdfa_def_template)
-    result = t.substitute(icc_profile=icc_profile,
-                          icc_identifier=icc_identifier,
-                          docinfo=docinfo)
-    return result
-
-
-def generate_pdfa_ps(target_filename, pdfmark, icc='sRGB'):
     if icc == 'sRGB':
         icc_profile = SRGB_ICC_PROFILE
     else:
         raise NotImplementedError("Only supporting sRGB")
 
-    # pdfmark must contain the full path to the ICC profile, and pdfmark must
+    # pdfmark must contain the full path to the ICC profile, and pdfmark must be
     # also encoded in ASCII. ocrmypdf can be installed anywhere, including to
     # paths that have a non-ASCII character in the filename. Ghostscript
     # accepts hex-encoded strings and converts them to byte strings, so
@@ -233,7 +116,8 @@ def generate_pdfa_ps(target_filename, pdfmark, icc='sRGB'):
     hex_icc_profile = hexlify(bytes_icc_profile)
     icc_profile = '<' + hex_icc_profile.decode('ascii') + '>'
 
-    ps = _get_pdfa_def(icc_profile, icc, pdfmark)
+    t = Template(pdfa_def_template)
+    ps = t.substitute(icc_profile=icc_profile, icc_identifier=icc)
 
     # We should have encoded everything to pure ASCII by this point, and
     # to be safe, only allow ASCII in PostScript
@@ -243,41 +127,23 @@ def generate_pdfa_ps(target_filename, pdfmark, icc='sRGB'):
 def file_claims_pdfa(filename):
     """Determines if the file claims to be PDF/A compliant
 
-    Checking if a file is a truly compliant PDF/A is a massive undertaking
-    that no open source tool does properly.  Some commercial tools are
-    generally reliable (Acrobat).
-
-    This checks if the XMP metadata contains a PDF/A marker.
+    This only checks if the XMP metadata contains a PDF/A marker. It does not
+    do full PDF/A validation.
     """
 
-    xmp = file_to_dict(filename)
-    if not xmp:
-        return {'pass': False, 'output': 'pdf',
-                'conformance': 'No XMP metadata'}
-
-    if not consts.XMP_NS_PDFA_ID in xmp:
-        return {'pass': False, 'output': 'pdf',
-                'conformance': 'No PDF/A metadata in XMP'}
-
-    pdfa_node = xmp[consts.XMP_NS_PDFA_ID]
-    def read_node(node, key):
-        return next(
-            (v for k, v, meta in node if k == key), ''
-        )
-
-    part = read_node(pdfa_node, 'pdfaid:part')
-    conformance = read_node(pdfa_node, 'pdfaid:conformance')
-
-    part_conformance = part + conformance
+    pdf = pikepdf.open(filename)
+    pdfmeta = pdf.open_metadata()
+    if not pdfmeta.pdfa_status:
+        return {
+            'pass': False,
+            'output': 'pdf',
+            'conformance': 'No PDF/A metadata in XMP',
+        }
     valid_part_conforms = {'1A', '1B', '2A', '2B', '2U', '3A', '3B', '3U'}
-
-    conformance = 'PDF/A-{}'.format(
-        part_conformance)
-
+    conformance = f'PDF/A-{pdfmeta.pdfa_status}'
     pdfa_dict = {}
-    if part_conformance in valid_part_conforms:
+    if pdfmeta.pdfa_status in valid_part_conforms:
         pdfa_dict['pass'] = True
         pdfa_dict['output'] = 'pdfa'
     pdfa_dict['conformance'] = conformance
-
     return pdfa_dict

src/ocrmypdf/pdfinfo/__init__.py

@@ -16,36 +16,29 @@
 # You should have received a copy of the GNU General Public License
 # along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
 
-from decimal import Decimal
-from math import hypot, isclose
-import re
 from collections import namedtuple
-from pathlib import Path
+from decimal import Decimal
 from enum import Enum
-
-from .exec import ghostscript
-from .helpers import fspath
+from math import hypot, isclose
+from os import fspath
+from pathlib import Path
+from unittest.mock import Mock
+from warnings import warn
+import re
 
 from pikepdf import PdfMatrix
 import pikepdf
 
-Colorspace = Enum('Colorspace',
-                  'gray rgb cmyk lab icc index sep devn pattern jpeg2000')
+from . import ghosttext
 
-Encoding = Enum('Encoding',
-                'ccitt jpeg jpeg2000 jbig2 asciihex ascii85 lzw flate ' + \
-                'runlength')
+from ..exceptions import EncryptedPdfError, MissingDependencyError
 
-# Forgive me for I have sinned
-# I am using regular expressions to parse XML. However the XML in this case,
-# generated by Ghostscript, is self-consistent enough to be parseable.
-regex_remove_char_tags = re.compile(br"""
-    <char\b
-    (?:   [^>]   # anything single character but >
-        | \">\"  # special case: trap ">"
-    )*
-    />           # terminate with '/>'
-""", re.VERBOSE)
+
+Colorspace = Enum('Colorspace', 'gray rgb cmyk lab icc index sep devn pattern jpeg2000')
+
+Encoding = Enum(
+    'Encoding', 'ccitt jpeg jpeg2000 jbig2 asciihex ascii85 lzw flate ' + 'runlength'
+)
 
 FRIENDLY_COLORSPACE = {
     '/DeviceGray': Colorspace.gray,
@@ -76,7 +69,7 @@ FRIENDLY_ENCODING = {
     '/A85': Encoding.ascii85,
     '/LZW': Encoding.lzw,
     '/Fl': Encoding.flate,
-    '/RL': Encoding.runlength
+    '/RL': Encoding.runlength,
 }
 
 FRIENDLY_COMP = {
@@ -84,63 +77,48 @@ FRIENDLY_COMP = {
     Colorspace.rgb: 3,
     Colorspace.cmyk: 4,
     Colorspace.lab: 3,
-    Colorspace.index: 1
+    Colorspace.index: 1,
 }
 
 
 UNIT_SQUARE = (1.0, 0.0, 0.0, 1.0, 0.0, 0.0)
 
 
-def _matrix_from_shorthand(shorthand):
-    """Convert from PDF matrix shorthand to full matrix
-
-    PDF 1.7 spec defines a shorthand for describing the entries of a matrix
-    since the last column is always (0, 0, 1).
-    """
-
-    a, b, c, d, e, f = map(float, shorthand)
-    return ((a, b, 0),
-            (c, d, 0),
-            (e, f, 1))
-
-
-def _shorthand_from_matrix(matrix):
-    """Convert from transformation matrix to PDF shorthand."""
-    a, b = matrix[0][0], matrix[0][1]
-    c, d = matrix[1][0], matrix[1][1]
-    e, f = matrix[2][0], matrix[2][1]
-    return tuple(map(float, (a, b, c, d, e, f)))
-
-
 def _is_unit_square(shorthand):
     values = map(float, shorthand)
     pairwise = zip(values, UNIT_SQUARE)
     return all([isclose(a, b, rel_tol=1e-3) for a, b in pairwise])
 
-XobjectSettings = namedtuple('XobjectSettings',
-    ['name', 'shorthand', 'stack_depth'])
 
-InlineSettings = namedtuple('InlineSettings',
-    ['iimage', 'shorthand', 'stack_depth'])
+XobjectSettings = namedtuple('XobjectSettings', ['name', 'shorthand', 'stack_depth'])
 
-ContentsInfo = namedtuple('ContentsInfo',
-    ['xobject_settings', 'inline_images', 'found_text'])
+InlineSettings = namedtuple('InlineSettings', ['iimage', 'shorthand', 'stack_depth'])
+
+ContentsInfo = namedtuple(
+    'ContentsInfo', ['xobject_settings', 'inline_images', 'found_vector']
+)
+
+TextboxInfo = namedtuple('TextboxInfo', ['bbox', 'is_visible', 'is_corrupt'])
 
 
+class VectorInfo:
+    def __init__(self):
+        pass
 
-def _normalize_stack(operations):
-    """Convert runs of qQ's in the stack into single operations"""
-    for operands, command in operations:
-        command = str(command)
-        if re.match(r'Q*q+$', command):   # Zero or more Q, one or more q
-            for char in command:          # Split into individual
-                yield ([], char)          # Yield individual
+
+def _normalize_stack(graphobjs):
+    """Convert runs of qQ's in the stack into single graphobjs"""
+    for operands, operator in graphobjs:
+        operator = str(operator)
+        if re.match(r'Q*q+$', operator):  # Zero or more Q, one or more q
+            for char in operator:  # Split into individual
+                yield ([], char)  # Yield individual
         else:
-            yield (operands, command)
+            yield (operands, operator)
 
 
 def _interpret_contents(contentstream, initial_shorthand=UNIT_SQUARE):
-    """Interpret the PDF content stream
+    """Interpret the PDF content stream.
 
     The stack represents the state of the PDF graphics stack.  We are only
     interested in the current transformation matrix (CTM) so we only track
@@ -158,53 +136,66 @@ def _interpret_contents(contentstream, initial_shorthand=UNIT_SQUARE):
 
     PDF units suit our needs so we initialize ctm to the identity matrix.
 
+    According to the PDF specification, the maximum stack depth is 32. Other
+    viewers tolerate some amount beyond this.  We issue a warning if the
+    stack depth exceeds the spec limit and set a hard limit beyond this to
+    bound our memory requirements.  If the stack underflows behavior is
+    undefined in the spec, but we just pretend nothing happened and leave the
+    CTM unchanged.
     """
 
     stack = []
     ctm = PdfMatrix(initial_shorthand)
     xobject_settings = []
     inline_images = []
-    found_text = False
-    text_operators = set(['Tj', 'TJ', '"', "'"])
-    operator_whitelist = """q Q Do cm TJ Tj " ' BI ID EI"""
+    found_vector = False
+    vector_ops = set('S s f F f* B B* b b*'.split())
+    image_ops = set('BI ID EI q Q Do cm'.split())
+    operator_whitelist = ' '.join(vector_ops | image_ops)
 
-    for n, op in enumerate(_normalize_stack(
-            pikepdf.parse_content_stream(contentstream, operator_whitelist))):
-        operands, command = op
-
-        if command == 'q':
+    for n, graphobj in enumerate(
+        _normalize_stack(
+            pikepdf.parse_content_stream(contentstream, operator_whitelist)
+        )
+    ):
+        operands, operator = graphobj
+        if operator == 'q':
             stack.append(ctm)
-            if len(stack) > 32:
-                raise RuntimeError(
-                    "PDF graphics stack overflow, command %i" % n)
-        elif command == 'Q':
+            if len(stack) > 32:  # See docstring
+                if len(stack) > 128:
+                    raise RuntimeError(
+                        "PDF graphics stack overflowed hard limit, operator %i" % n
+                    )
+                warn("PDF graphics stack overflowed spec limit")
+        elif operator == 'Q':
             try:
                 ctm = stack.pop()
             except IndexError:
-                raise RuntimeError(
-                    "PDF graphics stack underflow, command %i" % n)
-        elif command == 'cm':
+                # Keeping the ctm the same seems to be the only sensible thing
+                # to do. Just pretend nothing happened, keep calm and carry on.
+                warn("PDF graphics stack underflowed - PDF may be malformed")
+        elif operator == 'cm':
             ctm = PdfMatrix(operands) @ ctm
-        elif command == 'Do':
+        elif operator == 'Do':
             image_name = operands[0]
             settings = XobjectSettings(
-                name=image_name, shorthand=ctm.shorthand,
-                stack_depth=len(stack))
+                name=image_name, shorthand=ctm.shorthand, stack_depth=len(stack)
+            )
             xobject_settings.append(settings)
-        elif command == 'INLINE IMAGE':
+        elif operator == 'INLINE IMAGE':  # BI/ID/EI are grouped into this
             iimage = operands[0]
             inline = InlineSettings(
-                iimage=iimage, shorthand=ctm.shorthand,
-                stack_depth=len(stack))
+                iimage=iimage, shorthand=ctm.shorthand, stack_depth=len(stack)
+            )
             inline_images.append(inline)
-        elif command in text_operators:
-            found_text = True
-
+        elif operator in vector_ops:
+            found_vector = True
 
     return ContentsInfo(
         xobject_settings=xobject_settings,
         inline_images=inline_images,
-        found_text=found_text)
+        found_vector=found_vector,
+    )
 
 
 def _get_dpi(ctm_shorthand, image_size):
@@ -274,8 +265,7 @@ def _get_dpi(ctm_shorthand, image_size):
 class ImageInfo:
     DPI_PREC = Decimal('1.000')
 
-    def __init__(self, *, name='', pdfimage=None, inline=None,
-                 shorthand=None):
+    def __init__(self, *, name='', pdfimage=None, inline=None, shorthand=None):
 
         self._name = str(name)
         self._shorthand = shorthand
@@ -360,19 +350,24 @@ class ImageInfo:
         return _get_dpi(self._shorthand, (self._width, self._height))[1]
 
     def __repr__(self):
-        class_locals = {attr: getattr(self, attr, None) for attr in dir(self)
-                        if not attr.startswith('_')}
+        class_locals = {
+            attr: getattr(self, attr, None)
+            for attr in dir(self)
+            if not attr.startswith('_')
+        }
         return (
             "<ImageInfo '{name}' {type_} {width}x{height} {color} "
-            "{comp} {bpc} {enc} {xres}x{yres}>").format(**class_locals)
+            "{comp} {bpc} {enc} {xres}x{yres}>"
+        ).format(**class_locals)
 
 
 def _find_inline_images(contentsinfo):
     "Find inline images in the contentstream"
 
     for n, inline in enumerate(contentsinfo.inline_images):
-        yield ImageInfo(name='inline-%02d' % n, shorthand=inline.shorthand,
-                        inline=inline)
+        yield ImageInfo(
+            name='inline-%02d' % n, shorthand=inline.shorthand, inline=inline
+        )
 
 
 def _image_xobjects(container):
@@ -396,6 +391,8 @@ def _image_xobjects(container):
     xobjs = resources['/XObject'].as_dict()
     for xobj in xobjs:
         candidate = xobjs[xobj]
+        if not '/Subtype' in candidate:
+            continue
         if candidate['/Subtype'] == '/Image':
             pdfimage = candidate
             yield (pdfimage, xobj)
@@ -408,7 +405,6 @@ def _find_regular_images(container, contentsinfo):
     that contains images.
 
     Generates images with their DPI at time of drawing.
-
     """
 
     for pdfimage, xobj in _image_xobjects(container):
@@ -427,8 +423,7 @@ def _find_regular_images(container, contentsinfo):
                 # these from our DPI calculation for the page.
                 continue
 
-            yield ImageInfo(name=draw.name, pdfimage=pdfimage, shorthand=
-                            draw.shorthand)
+            yield ImageInfo(name=draw.name, pdfimage=pdfimage, shorthand=draw.shorthand)
 
 
 def _find_form_xobject_images(pdf, container, contentsinfo):
@@ -458,11 +453,12 @@ def _find_form_xobject_images(pdf, container, contentsinfo):
             # but in practice both Form XObjects and multiple drawing of the
             # same object are both very rare.
             ctm_shorthand = settings.shorthand
-            yield from _find_images(
-                pdf=pdf, container=form_xobject, shorthand=ctm_shorthand)
+            yield from _process_content_streams(
+                pdf=pdf, container=form_xobject, shorthand=ctm_shorthand
+            )
 
 
-def _find_images(*, pdf, container, shorthand=None):
+def _process_content_streams(*, pdf, container, shorthand=None):
     """Find all individual instances of images drawn in the container
 
     Usually the container is a page, but it may also be a Form XObject.
@@ -471,7 +467,7 @@ def _find_images(*, pdf, container, shorthand=None):
     in an XObject.
 
     Form XObjects may include inline images, XObject images,
-    and recursively, other Form XObjects; and also vector drawing commands.
+    and recursively, other Form XObjects; and also vector graphic objects.
 
     Every instance of an image being drawn somewhere is flattened and
     treated as a unique image, since if the same image is drawn multiple times
@@ -483,8 +479,7 @@ def _find_images(*, pdf, container, shorthand=None):
 
     if container.get('/Type') == '/Page' and '/Contents' in container:
         initial_shorthand = shorthand or UNIT_SQUARE
-    elif container.get('/Type') == '/XObject' and \
-            container['/Subtype'] == '/Form':
+    elif container.get('/Type') == '/XObject' and container['/Subtype'] == '/Form':
         # Set the CTM to the state it was when the "Do" operator was
         # encountered that is drawing this instance of the Form XObject
         ctm = PdfMatrix(shorthand) if shorthand else PdfMatrix.identity()
@@ -503,62 +498,13 @@ def _find_images(*, pdf, container, shorthand=None):
 
     contentsinfo = _interpret_contents(container, initial_shorthand)
 
+    if contentsinfo.found_vector:
+        yield VectorInfo()
     yield from _find_inline_images(contentsinfo)
     yield from _find_regular_images(container, contentsinfo)
     yield from _find_form_xobject_images(pdf, container, contentsinfo)
 
 
-def _page_get_textblocks(infile, pageno):
-    """Smarter text detection"""
-    import xml.etree.ElementTree as ET
-
-    gstext = ghostscript.extract_text(infile, pageno+1)
-
-    # Remove all <char /> tags, because they might contain invalid XML entities
-    # like <char bbox="348 596 348 596" c="&#x1;"/> which chokes on the
-    # inclusion of U+0001. Understandably.
-    # Just remove the whole <char /> tag since we don't use it at all, and they
-    # are only generated as innermost self-closing tags.
-    gstext = regex_remove_char_tags.sub(b' ', gstext)
-
-    if gstext.strip() == '':
-        return []
-
-    try:
-        root = ET.fromstring(gstext)
-    except ET.ParseError as e:
-        return []  # If we can't parse, assume none...
-
-    def blocks():
-        for span in root.findall('.//span'):
-            bbox_str = span.attrib['bbox']
-            font_size = span.attrib['size']
-            pts = [int(pt) for pt in bbox_str.split()]
-            pts[1] = pts[1] - int(float(font_size) + 0.5)
-            bbox = tuple(pts)
-            yield bbox
-
-    def joined_blocks():
-        prev = None
-        for bbox in blocks():
-            if prev is None:
-                prev = bbox
-            if bbox[1] == prev[1] and bbox[3] == prev[3]:
-                gap = prev[2] - bbox[0]
-                height = bbox[3] - bbox[1]
-                if gap < height:
-                    # Join boxes
-                    prev = (prev[0], prev[1], bbox[2], bbox[3])
-                    continue
-            # yield previously joined bboxes and start anew
-            yield prev
-            prev = bbox
-        if prev is not None:
-            yield prev
-
-    return [block for block in joined_blocks()]
-
-
 def _page_has_text(text_blocks, page_width, page_height):
     """Smarter text detection that ignores text in margins"""
 
@@ -566,18 +512,19 @@ def _page_has_text(text_blocks, page_width, page_height):
 
     margin_ratio = 0.125
     interior_bbox = (
-        margin_ratio * pw, margin_ratio * ph,
-        (1 - margin_ratio) * pw, (1 - margin_ratio) * ph
+        margin_ratio * pw,  # left
+        (1 - margin_ratio) * ph,  # top
+        (1 - margin_ratio) * pw,  # right
+        margin_ratio * ph,  # bottom  (first quadrant: bottom < top)
     )
 
     def rects_intersect(a, b):
         """
         Where (a,b) are 4-tuple rects (left-0, top-1, right-2, bottom-3)
         https://stackoverflow.com/questions/306316/determine-if-two-rectangles-overlap-each-other
-        Negative signs to account for our coordinates being in the fourth quadrant
-        and the formula assuming the first
+        Formula assumes all boxes are in first quadrant
         """
-        return a[0] < b[2] and a[2] > b[0] and -a[1] > -b[3] and -a[3] < -b[1]
+        return a[0] < b[2] and a[2] > b[0] and a[1] > b[3] and a[3] < b[1]
 
     has_text = False
     for bbox in text_blocks:
@@ -587,21 +534,50 @@ def _page_has_text(text_blocks, page_width, page_height):
     return has_text
 
 
-def _pdf_get_pageinfo(pdf, pageno: int, infile):
+def simplify_textboxes(miner, textbox_getter):
+    """Extract only limited content from text boxes
+
+    We do this to save memory and ensure that our objects are pickleable.
+    """
+    for box in textbox_getter(miner):
+        first_line = box._objs[0]
+        first_char = first_line._objs[0]
+
+        visible = first_char.rendermode != 3
+        corrupt = first_char.get_text() == '\ufffd'
+        yield TextboxInfo(box.bbox, visible, corrupt)
+
+
+def _pdf_get_pageinfo(pdf, pageno: int, infile, xmltext):
     pageinfo = {}
     pageinfo['pageno'] = pageno
     pageinfo['images'] = []
 
     page = pdf.pages[pageno]
-
-    pageinfo['textinfo'] = _page_get_textblocks(fspath(infile), pageno)
-
     mediabox = [Decimal(d) for d in page.MediaBox.as_list()]
     width_pt = mediabox[2] - mediabox[0]
     height_pt = mediabox[3] - mediabox[1]
 
-    pageinfo['has_text'] = _page_has_text(
-        pageinfo['textinfo'], width_pt, height_pt)
+    if xmltext is not None:
+        bboxes = ghosttext.page_get_textblocks(
+            fspath(infile), pageno, xmltext=xmltext, height=height_pt
+        )
+        pageinfo['bboxes'] = bboxes
+    else:
+        # pdfminer required for this section
+        try:
+            from .layout import get_page_analysis, get_text_boxes
+        except ImportError:
+            raise MissingDependencyError(
+                "pdfminer is required for this feature. Your distribution "
+                "may not have installed it."
+            )
+        pscript5_mode = str(pdf.docinfo.get('/Creator')).startswith('PScript5')
+        miner = get_page_analysis(infile, pageno, pscript5_mode)
+        pageinfo['textboxes'] = list(simplify_textboxes(miner, get_text_boxes))
+        bboxes = (box.bbox for box in pageinfo['textboxes'])
+
+    pageinfo['has_text'] = _page_has_text(bboxes, width_pt, height_pt)
 
     userunit = page.get('/UserUnit', Decimal(1.0))
     if not isinstance(userunit, Decimal):
@@ -616,31 +592,55 @@ def _pdf_get_pageinfo(pdf, pageno: int, infile):
         pageinfo['rotate'] = 0
 
     userunit_shorthand = (userunit, 0, 0, userunit, 0, 0)
-    pageinfo['images'] = [im for im in
-                          _find_images(pdf=pdf, container=page,
-                                       shorthand=userunit_shorthand)]
+    contentsinfo = [
+        ci
+        for ci in _process_content_streams(
+            pdf=pdf, container=page, shorthand=userunit_shorthand
+        )
+    ]
+
+    pageinfo['has_vector'] = False
+    if any(isinstance(ci, VectorInfo) for ci in contentsinfo):
+        pageinfo['has_vector'] = True
+
+    pageinfo['images'] = [im for im in contentsinfo if isinstance(im, ImageInfo)]
     if pageinfo['images']:
         xres = Decimal(max(image.xres for image in pageinfo['images']))
         yres = Decimal(max(image.yres for image in pageinfo['images']))
         pageinfo['xres'], pageinfo['yres'] = xres, yres
-        pageinfo['width_pixels'] = \
-            int(round(xres * pageinfo['width_inches']))
-        pageinfo['height_pixels'] = \
-            int(round(yres * pageinfo['height_inches']))
+        pageinfo['width_pixels'] = int(round(xres * pageinfo['width_inches']))
+        pageinfo['height_pixels'] = int(round(yres * pageinfo['height_inches']))
 
     return pageinfo
 
 
-def _pdf_get_all_pageinfo(infile):
+def _pdf_get_all_pageinfo(infile, detailed_analysis=False, log=None):
+    if not log:
+        log = Mock()
+
     pdf = pikepdf.open(infile)
-    return [PageInfo(pdf, n, infile) for n in range(len(pdf.pages))]
+    if pdf.is_encrypted:
+        raise EncryptedPdfError()  # Triggered by encryption with empty passwd
+    if detailed_analysis:
+        pages_xml = None
+    else:
+        pages_xml = ghosttext.extract_text_xml(infile, pdf, pageno=None, log=log)
+
+    pages = []
+    for n in range(len(pdf.pages)):
+        page_xml = pages_xml[n] if pages_xml else None
+        page = PageInfo(pdf, n, infile, page_xml, detailed_analysis)
+        pages.append(page)
+
+    return pages, pdf
 
 
 class PageInfo:
-    def __init__(self, pdf, pageno, infile):
+    def __init__(self, pdf, pageno, infile, xmltext, detailed_analysis=False):
         self._pageno = pageno
         self._infile = infile
-        self._pageinfo = _pdf_get_pageinfo(pdf, pageno, infile)
+        self._pageinfo = _pdf_get_pageinfo(pdf, pageno, infile, xmltext)
+        self._detailed_analysis = detailed_analysis
 
     @property
     def pageno(self):
@@ -650,6 +650,16 @@ class PageInfo:
     def has_text(self):
         return self._pageinfo['has_text']
 
+    @property
+    def has_corrupt_text(self):
+        if not self._detailed_analysis:
+            raise NotImplementedError('Did not do detailed analysis')
+        return any(tbox.is_corrupt for tbox in self._pageinfo['textboxes'])
+
+    @property
+    def has_vector(self):
+        return self._pageinfo['has_vector']
+
     @property
     def width_inches(self):
         return self._pageinfo['width_inches']
@@ -681,8 +691,27 @@ class PageInfo:
     def images(self):
         return self._pageinfo['images']
 
-    def get_textareas(self):
-        yield from self._pageinfo['textinfo']
+    def get_textareas(self, visible=None, corrupt=None):
+        def predicate(obj, want_visible, want_corrupt):
+            result = True
+            if want_visible is not None:
+                if obj.is_visible != want_visible:
+                    result = False
+            if want_corrupt is not None:
+                if obj.is_corrupt != want_corrupt:
+                    result = False
+            return result
+
+        if 'textboxes' not in self._pageinfo:
+            if visible is not None and corrupt is not None:
+                raise NotImplementedError('Ghostscript textboxes cannot be classified')
+            return self._pageinfo['bboxes']
+
+        return (
+            obj.bbox
+            for obj in self._pageinfo['textboxes']
+            if predicate(obj, visible, corrupt)
+        )
 
     @property
     def xres(self):
@@ -705,21 +734,28 @@ class PageInfo:
 
     def __repr__(self):
         return (
-            '<PageInfo '
-            'pageno={} {}"x{}" rotation={} res={}x{} has_text={}>').format(
-            self.pageno, self.width_inches, self.height_inches,
+            '<PageInfo ' 'pageno={} {}"x{}" rotation={} res={}x{} has_text={}>'
+        ).format(
+            self.pageno,
+            self.width_inches,
+            self.height_inches,
             self.rotation,
-            self.xres, self.yres, self.has_text
+            self.xres,
+            self.yres,
+            self.has_text,
         )
 
 
 class PdfInfo:
-    """Get summary information about a PDF
+    """Get summary information about a PDF"""
 
-    """
-    def __init__(self, infile):
+    def __init__(self, infile, detailed_page_analysis=False, log=None):
         self._infile = infile
-        self._pages = _pdf_get_all_pageinfo(infile)
+        self._pages, pdf = _pdf_get_all_pageinfo(
+            infile, detailed_page_analysis, log=log
+        )
+        self._needs_rendering = pdf.root.get('/NeedsRendering', False)
+        self._has_acroform = '/AcroForm' in pdf.root
 
     @property
     def pages(self):
@@ -734,12 +770,20 @@ class PdfInfo:
     def has_userunit(self):
         return any(page.userunit != 1.0 for page in self.pages)
 
+    @property
+    def has_acroform(self):
+        return self._has_acroform
+
     @property
     def filename(self):
         if not isinstance(self._infile, (str, Path)):
             raise NotImplementedError("can't get filename from stream")
         return self._infile
 
+    @property
+    def needs_rendering(self):
+        return self._needs_rendering
+
     def __getitem__(self, item):
         return self._pages[item]
 
@@ -747,24 +791,18 @@ class PdfInfo:
         return len(self._pages)
 
     def __repr__(self):
-        return "<PdfInfo('...'), page count={}>".format(len(self))
-
-    # def __getstate__(self):
-    #     state = {'_infile': self._infile}
-    #     return state
-    #
-    # def __setstate__(self, state):
-    #     self._infile = state['_infile']
-    #     self._pages = _pdf_get_all_pageinfo(self._infile)
+        return f"<PdfInfo('...'), page count={len(self)}>"
 
 
 def main():
     import argparse
+
     parser = argparse.ArgumentParser()
     parser.add_argument('infile')
     args = parser.parse_args()
     info = _pdf_get_all_pageinfo(args.infile)
     from pprint import pprint
+
     pprint(info)
 
 

src/ocrmypdf/pdfinfo/ghosttext.py

@@ -0,0 +1,98 @@
+# © 2018 James R. Barlow: github.com/jbarlow83
+#
+# This file is part of OCRmyPDF.
+#
+# OCRmyPDF is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# OCRmyPDF is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
+
+import re
+import xml.etree.ElementTree as ET
+
+from ..exec import ghostscript
+
+# Forgive me for I have sinned
+# I am using regular expressions to parse XML. However the XML in this case,
+# generated by Ghostscript, is self-consistent enough to be parseable.
+regex_remove_char_tags = re.compile(
+    br"""
+    <char\b
+    (?:   [^>]   # anything single character but >
+        | \">\"  # special case: trap ">"
+    )*
+    />           # terminate with '/>'
+""",
+    re.VERBOSE,
+)
+
+
+def page_get_textblocks(infile, pageno, xmltext, height):
+    """Get text boxes out of Ghostscript txtwrite xml"""
+
+    root = xmltext
+    if not hasattr(xmltext, 'findall'):
+        return []
+
+    def blocks():
+        for span in root.findall('.//span'):
+            bbox_str = span.attrib['bbox']
+            font_size = span.attrib['size']
+            pts = [int(pt) for pt in bbox_str.split()]
+            pts[1] = pts[1] - int(float(font_size) + 0.5)
+            bbox_topdown = tuple(pts)
+            bb = bbox_topdown
+            bbox_bottomup = (bb[0], height - bb[3], bb[2], height - bb[1])
+            yield bbox_bottomup
+
+    def joined_blocks():
+        prev = None
+        for bbox in blocks():
+            if prev is None:
+                prev = bbox
+            if bbox[1] == prev[1] and bbox[3] == prev[3]:
+                gap = prev[2] - bbox[0]
+                height = abs(bbox[3] - bbox[1])
+                if gap < height:
+                    # Join boxes
+                    prev = (prev[0], prev[1], bbox[2], bbox[3])
+                    continue
+            # yield previously joined bboxes and start anew
+            yield prev
+            prev = bbox
+        if prev is not None:
+            yield prev
+
+    return [block for block in joined_blocks()]
+
+
+def extract_text_xml(infile, pdf, pageno=None, log=None):
+    existing_text = ghostscript.extract_text(infile, pageno=None)
+    existing_text = regex_remove_char_tags.sub(b' ', existing_text)
+
+    try:
+        root = ET.fromstringlist([b'<document>\n', existing_text, b'</document>\n'])
+        page_xml = root.findall('page')
+    except ET.ParseError as e:
+        log.error(
+            "An error occurred while attempting to retrieve existing text in "
+            "the input file. Will attempt to continue assuming that there is "
+            "no existing text in the file. The error was:"
+        )
+        log.error(e)
+        page_xml = [None] * len(pdf.pages)
+
+    page_count_difference = len(pdf.pages) - len(page_xml)
+    if page_count_difference != 0:
+        log.error("The number of pages in the input file is inconsistent.")
+        if page_count_difference > 0:
+            page_xml.extend([None] * page_count_difference)
+    return page_xml

src/ocrmypdf/pdfinfo/layout.py

@@ -0,0 +1,299 @@
+# © 2018 James R. Barlow: github.com/jbarlow83
+#
+# This file is part of OCRmyPDF.
+#
+# OCRmyPDF is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# OCRmyPDF is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.
+
+import re
+from math import copysign
+from pathlib import Path
+from unittest.mock import patch
+
+import pdfminer.encodingdb
+import pdfminer.pdfdevice
+import pdfminer.pdfinterp
+from pdfminer.converter import PDFLayoutAnalyzer
+from pdfminer.glyphlist import glyphname2unicode
+from pdfminer.layout import LAParams, LTChar, LTPage, LTTextBox
+from pdfminer.pdfdocument import PDFTextExtractionNotAllowed
+from pdfminer.pdffont import PDFFont, PDFSimpleFont, PDFUnicodeNotDefined
+from pdfminer.pdfpage import PDFPage
+from pdfminer.utils import bbox2str, matrix2str
+
+from ..exceptions import EncryptedPdfError
+
+STRIP_NAME = re.compile(r'[0-9]+')
+
+#
+# Unconditional pdfminer patches
+#
+
+
+def name2unicode(name):
+    """Fix pdfminer's name2unicode function
+
+    Font cids that are mapped to names of the form /g123 seem to be, by convention
+    characters with no corresponding Unicode entry. These can be subsetted fonts
+    or symbolic fonts. There seems to be no way to map /g123 fonts to Unicode,
+    barring a ToUnicode data structure.
+    """
+    if name in glyphname2unicode:
+        return glyphname2unicode[name]
+    if name.startswith('g') or name.startswith('a'):
+        raise KeyError(name)
+    if name.startswith('uni'):
+        try:
+            return chr(int(name[3:], 16))
+        except ValueError:  # Not hexadecimal
+            raise KeyError(name)
+    m = STRIP_NAME.search(name)
+    if not m:
+        raise KeyError(name)
+    return chr(int(m.group(0)))
+
+
+pdfminer.encodingdb.name2unicode = name2unicode
+
+original_PDFFont_init = PDFFont.__init__
+
+
+def PDFFont__init__(self, descriptor, widths, default_width=None):
+    original_PDFFont_init(self, descriptor, widths, default_width)
+    # PDF spec says descent should be negative
+    # A font with a positive descent implies it floats entirely above the
+    # baseline, i.e. it's not really a baseline anymore. I have fonts that
+    # claim a positive descent, but treating descent as positive always seems
+    # to misposition text.
+    if self.descent > 0:
+        self.descent = -self.descent
+
+
+PDFFont.__init__ = PDFFont__init__
+
+original_PDFSimpleFont_init = PDFSimpleFont.__init__
+
+
+def PDFSimpleFont__init__(self, descriptor, widths, spec):
+    # Font encoding is specified either by a name of
+    # built-in encoding or a dictionary that describes
+    # the differences.
+    original_PDFSimpleFont_init(self, descriptor, widths, spec)
+    # pdfminer is incorrect. If there is no ToUnicode and no Encoding, do not
+    # assume Unicode conversion is possible. RM 9.10.2
+    if not self.unicode_map and 'Encoding' not in spec:
+        self.cid2unicode = {}
+    return
+
+
+PDFSimpleFont.__init__ = PDFSimpleFont__init__
+#
+# pdfminer patches when creator is PScript5.dll
+#
+
+
+def PDFType3Font__PScript5_get_height(self):
+    h = self.bbox[3] - self.bbox[1]
+    if h == 0:
+        h = self.ascent - self.descent
+    return h * copysign(1.0, self.vscale)
+
+
+def PDFType3Font__PScript5_get_descent(self):
+    return self.descent * copysign(1.0, self.vscale)
+
+
+def PDFType3Font__PScript5_get_ascent(self):
+    return self.ascent * copysign(1.0, self.vscale)
+
+
+class LTStateAwareChar(LTChar):
+    """A subclass of LTChar that tracks text render mode at time of drawing"""
+
+    __slots__ = (
+        'rendermode',
+        '_text',
+        'matrix',
+        'fontname',
+        'adv',
+        'upright',
+        'size',
+        'width',
+        'height',
+        'bbox',
+        'x0',
+        'x1',
+        'y0',
+        'y1',
+    )
+
+    def __init__(
+        self,
+        matrix,
+        font,
+        fontsize,
+        scaling,
+        rise,
+        text,
+        textwidth,
+        textdisp,
+        ncs,
+        graphicstate,
+        textstate,
+    ):
+        super().__init__(
+            matrix,
+            font,
+            fontsize,
+            scaling,
+            rise,
+            text,
+            textwidth,
+            textdisp,
+            ncs,
+            graphicstate,
+        )
+        self.rendermode = textstate.render
+
+    def is_compatible(self, obj):
+        """Check if characters can be combined into a textline
+
+        We consider characters compatible if:
+            - the Unicode mapping is known, and both have the same render mode
+            - the Unicode mapping is unknown but both are part of the same font
+        """
+        both_unicode_mapped = isinstance(self._text, str) and isinstance(obj._text, str)
+        try:
+            if both_unicode_mapped:
+                return self.rendermode == obj.rendermode
+            font0, _ = self._text
+            font1, _ = obj._text
+            return font0 == font1 and self.rendermode == obj.rendermode
+        except (ValueError, AttributeError):
+            return False
+
+    def get_text(self):
+        if isinstance(self._text, tuple):
+            return '�'
+        return self._text
+
+    def __repr__(self):
+        return '<%s %s matrix=%s rendermode=%r font=%r adv=%s text=%r>' % (
+            self.__class__.__name__,
+            bbox2str(self.bbox),
+            matrix2str(self.matrix),
+            self.rendermode,
+            self.fontname,
+            self.adv,
+            self.get_text(),
+        )
+
+
+class TextPositionTracker(PDFLayoutAnalyzer):
+    """A page layout analyzer that pays attention to text visibility"""
+
+    def __init__(self, rsrcmgr, pageno=1, laparams=None):
+        super().__init__(rsrcmgr, pageno, laparams)
+        self.textstate = None
+        self.result = None
+
+    def begin_page(self, page, ctm):
+        super().begin_page(page, ctm)
+        self.cur_item = LTPage(self.pageno, page.mediabox)
+
+    def end_page(self, page):
+        assert not self._stack, str(len(self._stack))
+        assert isinstance(self.cur_item, LTPage), str(type(self.cur_item))
+        if self.laparams is not None:
+            self.cur_item.analyze(self.laparams)
+        self.pageno += 1
+        self.receive_layout(self.cur_item)
+
+    def render_string(self, textstate, seq, ncs, graphicstate):
+        self.textstate = textstate.copy()
+        super().render_string(self.textstate, seq, ncs, graphicstate)
+
+    def render_char(
+        self, matrix, font, fontsize, scaling, rise, cid, ncs, graphicstate
+    ):
+        try:
+            text = font.to_unichr(cid)
+            assert isinstance(text, str), str(type(text))
+        except PDFUnicodeNotDefined:
+            text = self.handle_undefined_char(font, cid)
+        textwidth = font.char_width(cid)
+        textdisp = font.char_disp(cid)
+        item = LTStateAwareChar(
+            matrix,
+            font,
+            fontsize,
+            scaling,
+            rise,
+            text,
+            textwidth,
+            textdisp,
+            ncs,
+            graphicstate,
+            self.textstate,
+        )
+        self.cur_item.add(item)
+        return item.adv
+
+    def handle_undefined_char(self, font, cid):
+        # log.info('undefined: %r, %r', font, cid)
+        return (font.fontname, cid)
+
+    def receive_layout(self, ltpage):
+        self.result = ltpage
+
+    def get_result(self):
+        return self.result
+
+
+def get_page_analysis(infile, pageno, pscript5_mode):
+    rman = pdfminer.pdfinterp.PDFResourceManager(caching=True)
+    dev = TextPositionTracker(rman, laparams=LAParams())
+    interp = pdfminer.pdfinterp.PDFPageInterpreter(rman, dev)
+
+    if pscript5_mode:
+        patcher = patch.multiple(
+            'pdfminer.pdffont.PDFType3Font',
+            spec=True,
+            get_ascent=PDFType3Font__PScript5_get_ascent,
+            get_descent=PDFType3Font__PScript5_get_descent,
+            get_height=PDFType3Font__PScript5_get_height,
+        )
+        patcher.start()
+
+    try:
+        with Path(infile).open('rb') as f:
+            page = PDFPage.get_pages(f, pagenos=[pageno], maxpages=0)
+            interp.process_page(next(page))
+    except PDFTextExtractionNotAllowed:
+        raise EncryptedPdfError()
+    finally:
+        if pscript5_mode:
+            patcher.stop()
+
+    return dev.get_result()
+
+
+def get_text_boxes(obj):
+    for child in obj:
+        if isinstance(child, (LTTextBox)):
+            yield child
+        else:
+            try:
+                yield from get_text_boxes(child)
+            except TypeError:
+                continue

tests/cache/2400dpi/__-l__eng__000001.ocr.png__000001.text__pdf__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/2400dpi/__-l__eng__000001.ocr.png__000001.text__pdf__txt/txt.bin

@@ -1,25 +1,25 @@
-é la Waterman
+a la Waterman
 
-h ens linzen
+4 ons linzen
 
 3 liter water
 
-3 mien
+3 uien
 
-bloem} hater
+bloem, boter
 
 2 kopjes melk
 
-laurier, kruidnagel, kerrie, gout
-
-Be linzen wassen en in¢l liter kokend wa-
-ter 1 dag laten weken. 2 liter water bi'
-de linzen voegen, gender hat water wagrin
-ze geweekt zijn af te gieten. De helft Van
-de mien bakken met laurier en kruiénagal.
-Alla mien, kerrie en zout bij de linzen
-voegen. A1135 aan de Rook brengem. Van de
-bloem mat boter-en melk een papje maken en
-verder afmaken met de soap. A13 de linzen
-gaar zijn is de seep klaar.
+laurier, kruidnagel, kerrie, zout
 
+De linzgen wassen en in -l liter kokend wa-
+ter 1 dag laten weken, 2 liter water bij
+de linzen voegen, zonder het water waarin
+ze geweekt zijn af te gieten, De helft van
+de uien bakken met laurier en Kruicdnagel.
+Alle uien, kerrie en gout bij de linzen
+voegen, Alles aan de kook brengen,. Van de
+bloem met boter en melk een papje maken en
+verder afmaken met de soep, Als de linzen
+gaar Zijn is de soep klaar.
+

tests/cache/aspect/__-l__eng__000001.ocr.png__000001.text__pdf__txt/stderr.bin

@@ -1,3 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
-Too few characters. Skipping this page
-OSD: Weak margin (0.00) for 24 blob text block, but using orientation anyway: 0
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/aspect/__-l__eng__000001.ocr.png__000001.text__pdf__txt/txt.bin

@@ -1,4 +1,4 @@
  
 
-This shnuld be a perfect circle-
-
+This should be a perfect circle:
+

tests/cache/aspect/__-l__eng__000001.ocr.png__000001__hocr__txt/hocr.bin

@@ -5,20 +5,27 @@
  <head>
   <title></title>
 <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
-  <meta name='ocr-system' content='tesseract 3.05.01' />
-  <meta name='ocr-capabilities' content='ocr_page ocr_carea ocr_par ocr_line ocrx_word'/>
+  <meta name='ocr-system' content='tesseract 4.0.0' />
+  <meta name='ocr-capabilities' content='ocr_page ocr_carea ocr_par ocr_line ocrx_word ocrp_wconf'/>
 </head>
 <body>
-  <div class='ocr_page' id='page_1' title='image "/var/folders/37/78_114p552q16vv6vmgm5kr00000gn/T/com.github.ocrmypdf.7vjmeixk/000001.ocr.png"; bbox 0 0 1000 800; ppageno 0'>
+  <div class='ocr_page' id='page_1' title='image "/var/folders/37/78_114p552q16vv6vmgm5kr00000gn/T/com.github.ocrmypdf.jz4b2s0s/000001.ocr.png"; bbox 0 0 1000 800; ppageno 0'>
    <div class='ocr_carea' id='block_1_1' title="bbox 296 96 704 504">
     <p class='ocr_par' id='par_1_1' lang='eng' title="bbox 296 96 704 504">
-     <span class='ocr_line' id='line_1_1' title="bbox 296 96 704 504; baseline 0 296; x_size 169.33333; x_descenders 42.333332; x_ascenders 42.333336"><span class='ocrx_word' id='word_1_1' title='bbox 296 96 704 504; x_wconf 95'><strong> </strong></span> 
+     <span class='ocr_line' id='line_1_1' title="bbox 296 96 704 504; baseline 0 296; x_size 169.33333; x_descenders 42.333332; x_ascenders 42.333336">
+      <span class='ocrx_word' id='word_1_1' title='bbox 296 96 704 504; x_wconf 95'><strong><em> </em></strong></span>
      </span>
     </p>
    </div>
    <div class='ocr_carea' id='block_1_2' title="bbox 150 592 841 622">
     <p class='ocr_par' id='par_1_2' lang='eng' title="bbox 150 592 841 622">
-     <span class='ocr_line' id='line_1_2' title="bbox 150 592 841 622; baseline 0 -6; x_size 30; x_descenders 6; x_ascenders 8"><span class='ocrx_word' id='word_1_2' title='bbox 150 592 230 616; x_wconf 85'><strong>This</strong></span> <span class='ocrx_word' id='word_1_3' title='bbox 260 592 384 616; x_wconf 81'>shnuld</span> <span class='ocrx_word' id='word_1_4' title='bbox 413 592 449 616; x_wconf 81'><strong>be</strong></span> <span class='ocrx_word' id='word_1_5' title='bbox 479 600 493 616; x_wconf 85'><em>a</em></span> <span class='ocrx_word' id='word_1_6' title='bbox 523 592 668 622; x_wconf 76'>perfect</span> <span class='ocrx_word' id='word_1_7' title='bbox 698 592 841 616; x_wconf 76'><strong>circle-</strong></span> 
+     <span class='ocr_line' id='line_1_2' title="bbox 150 592 841 622; baseline 0 -6; x_size 30; x_descenders 6; x_ascenders 8">
+      <span class='ocrx_word' id='word_1_2' title='bbox 150 592 230 616; x_wconf 96'><strong><em>This</em></strong></span>
+      <span class='ocrx_word' id='word_1_3' title='bbox 260 592 384 616; x_wconf 95'><strong><em>should</em></strong></span>
+      <span class='ocrx_word' id='word_1_4' title='bbox 413 592 449 616; x_wconf 95'><strong><em>be</em></strong></span>
+      <span class='ocrx_word' id='word_1_5' title='bbox 479 600 493 616; x_wconf 95'><strong><em>a</em></strong></span>
+      <span class='ocrx_word' id='word_1_6' title='bbox 523 592 668 622; x_wconf 95'><strong><em>perfect</em></strong></span>
+      <span class='ocrx_word' id='word_1_7' title='bbox 698 592 841 616; x_wconf 55'><strong><em>circle:</em></strong></span>
      </span>
     </p>
    </div>

tests/cache/aspect/__-l__eng__000001.ocr.png__000001__hocr__txt/stderr.bin

@@ -1,3 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
-Too few characters. Skipping this page
-OSD: Weak margin (0.00) for 24 blob text block, but using orientation anyway: 0
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/aspect/__-l__eng__000001.ocr.png__000001__hocr__txt/txt.bin

@@ -1,4 +1,4 @@
  
 
-This shnuld be a perfect circle-
-
+This should be a perfect circle:
+

tests/cache/cardinal/__-l__eng__000001.ocr.png__000001.text__pdf__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/cardinal/__-l__eng__000001.ocr.png__000001.text__pdf__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first‘track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHz 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cardinal/__-l__eng__000001.ocr.png__000001__hocr__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/cardinal/__-l__eng__000001.ocr.png__000001__hocr__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first‘track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHz 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cardinal/__-l__eng__000002.ocr.png__000002.text__pdf__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/cardinal/__-l__eng__000002.ocr.png__000002.text__pdf__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first‘track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHz 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cardinal/__-l__eng__000002.ocr.png__000002__hocr__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/cardinal/__-l__eng__000002.ocr.png__000002__hocr__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first‘track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHz 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cardinal/__-l__eng__000003.ocr.png__000003.text__pdf__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/cardinal/__-l__eng__000003.ocr.png__000003.text__pdf__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first‘track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHz 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cardinal/__-l__eng__000003.ocr.png__000003__hocr__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/cardinal/__-l__eng__000003.ocr.png__000003__hocr__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first‘track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHz 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cardinal/__-l__eng__000004.ocr.png__000004.text__pdf__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/cardinal/__-l__eng__000004.ocr.png__000004.text__pdf__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first‘track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHz 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cardinal/__-l__eng__000004.ocr.png__000004__hocr__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/cardinal/__-l__eng__000004.ocr.png__000004__hocr__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first‘track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHz 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cardinal/__-l__osd__--psm__0__000001.ocr.preview.jpg__stdout/stdout.bin

@@ -1,6 +1,6 @@
 Page number: 0
 Orientation in degrees: 0
 Rotate: 0
-Orientation confidence: 18.91
+Orientation confidence: 34.40
 Script: Latin
-Script confidence: 0.97
+Script confidence: 2.90

tests/cache/cardinal/__-l__osd__--psm__0__000002.ocr.preview.jpg__stdout/stdout.bin

@@ -1,6 +1,6 @@
 Page number: 0
 Orientation in degrees: 90
 Rotate: 270
-Orientation confidence: 17.21
+Orientation confidence: 34.53
 Script: Latin
-Script confidence: 1.06
+Script confidence: 3.83

tests/cache/cardinal/__-l__osd__--psm__0__000003.ocr.preview.jpg__stdout/stdout.bin

@@ -1,6 +1,6 @@
 Page number: 0
 Orientation in degrees: 180
 Rotate: 180
-Orientation confidence: 14.79
+Orientation confidence: 31.79
 Script: Latin
-Script confidence: 2.87
+Script confidence: 3.18

tests/cache/cardinal/__-l__osd__--psm__0__000004.ocr.preview.jpg__stdout/stdout.bin

@@ -1,6 +1,6 @@
 Page number: 0
 Orientation in degrees: 270
 Rotate: 90
-Orientation confidence: 19.19
+Orientation confidence: 32.59
 Script: Latin
-Script confidence: 0.58
+Script confidence: 2.85

tests/cache/ccitt/__-l__eng__000001.ocr.png__000001.text__pdf__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/ccitt/__-l__eng__000001.ocr.png__000001.text__pdf__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHZ 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/ccitt/__-l__eng__000001.ocr.png__000001__hocr__txt/stderr.bin

@@ -1 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica

tests/cache/ccitt/__-l__eng__000001.ocr.png__000001__hocr__txt/txt.bin

@@ -1,51 +1,51 @@
 The LinnSequencer
 32 Track MIDI Sequence Recorder
 
-The LinnSequencer is a state—of—the-art composition and performance tool for the professional musician. It is
+The LinnSequencer is a state-of-the-art composition and performance tool for the professional musician. It is
 
 extremely powerful, yet amazingly simple to learn and use. It’s many remarkable features include:
 
-0 Operation is similar to multi—track tape recorder with PLAY, STOP, RECORD, FAST
+¢ Operation is similar to multi-track tape recorder with PLAY, STOP, RECORD, FAST
 FORWARD, REWIND, and LOCATE controls.
 
-0 Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
+e Each of the 100 sequences contains 32 simultaneous, polyphonic tracks. Each track may
 be assigned to one of 16 MIDI channels. Simultaneously plays up to 16 polyphonic
 
-synthesizers !
+synthesizers!
 
-0 Ultra—fast 3 1/2 ” disk drive stores complex songs in seconds and holds over 110,000 notes
+¢ Ultra-fast 3%” disk drive stores complex songs in seconds and holds over 110,000 notes
 
 per disk!
 
-0 One or all tracks may be TRANSPOSED at the touch of a key.
-0 Exclusive real—time ERASE function makes editing FAST.
-0 Exclusive REPEAT function automatically repeats any held notes at a pre-selected
+¢ One or all tracks may be TRANSPOSED at the touch of a key.
+e Exclusive real-time ERASE function makes editing FAST.
+* Exclusive REPEAT function automatically repeats any held notes at a pre-selected
 
 rhythmic value.
 
-0 TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
+¢ TIMING CORRECTION works during playback and operates without ‘chopping’ notes.
 
-0 Optional SMPTE time code synchronization.
+¢ Optional SMPTE time code synchronization.
 
-0 Optional remote control.
+© Optional remote control.
 
-Recording 3 Sequence
+Recording a Sequence
 
 To record a sequence, simply press RECORD and PLAY,
 then play your MIDI keyboard in time to the Sequencer’s
 click track. When the sequence loops back around to bar 1,
-you’ll hear what you played—only all timing errors will be
+you’ ll hear what you played—only all timing errors will be
 
 corrected! (Timing correction may be adjusted or defeated).
 
 Any additional notes played will be added into the track
-—existing notes are not erased while recording!
+— existing notes are not erased while recording!
 
 FAST FORWARD, REWIND, and LOCATE controls
 may be used at any time to quickly access any location in
-your sequence for spot—recording. To overdub a new part,
-select a different track and start recording~while you
-record, the first track will play in perfect sync (unless you
+your sequence for spot-recording. To overdub a new part,
+select a different track and start recording—while you
+record, the first track will play in perfect sync (unless you
 MUTE it, or SOLO another track). In this way, up to 32
 tracks may be overdubbed! All MIDI effects are recorded
 including pitch bend, modulation, velocity, aftertouch,
@@ -58,7 +58,7 @@ the note to be erased just before it plays in the sequence—
 when played back, it will be gone. Notes may also be
 
 added, erased, or changed using the SINGLE STEP func-
-tion. To overdub notes at specific points within a sequence,
+tion. To overdub notes at specific points within a sequence,
 
 Additional Features
 
@@ -70,7 +70,7 @@ from one location to another—in the same sequence or a
 different one. For example, you might insert a copy of the
 first verse between the second chorus and the bridge.
 DELETE BARS operates the same way to remove
-unwanted sections.
+unwanted sections,
 
 Creating a Song
 
@@ -90,34 +90,34 @@ the LinnSequencer is designed to let you compose, record
 and edit while devoting your undivided attention to your
 music. See your Linn dealer today for a demonstration!
 
-0 Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
+* Simple, easy to learn operation—the 32 character LCD display clearly guides you through all operations. If needed, the
 
 HELP button displays additional explanations.
 
-0 Non-destructive recording—existing notes are not erased while recording.
-0 Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
+* Non-destructive recording—existing notes are not erased while recording.
+¢ Two FOOTSWITCH INPUTS may be assigned to remotely control many of the commonly used functions, including
 
 ERASE, REPEAT, PLAY/STOP, or LOCATE.
 
-0 Two TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
+¢ Iwo TRIGGER OUTPUTS may be programmed to output pulses at any selected note value.
 
-0 Will sync to standard LinnDrum or Linn 9000 sync tone.
+© Will sync to standard LinnDrum or Linn 9000 sync tone.
 
-' Utilizes ultra high—speed, 8 MHZ 80186 16 bit computer internally for FAST operation.
-0 TEMPO may be specified in BEATS-PER—MINUTE or FRAMES-PER—BEAT at 24, 25, or 30 frames per second,
+© Utilizes ultra high-speed, 8 MHz 80186 16 bit computer internally for FAST operation.
+* TEMPO may be specified in BEATS-PER-MINUTE or FRAMES-PER-BEAT at 24, 25, or 30 frames per second,
 
 (even drop frame!)
 
-0 TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
+¢ TEMPO may be entered numerically, adjustable in tenths of a Beat-Per-Minute increments, or by tapping quarter notes
 
 on the TAP TEMPO button.
 
-0 TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
-° Any TIME SIGNATURE may be used, and may be changed within a song.
+¢ TEMPO CHANGES may be programmed into a sequence, with smooth transitions if desired.
+¢ Any TIME SIGNATURE may be used, and may be changed within a song.
 
-E1111
+linn
 Linn Electronics, Inc.
 
 18720 Oxnard Street, Tarzana, CA 91356
-(818) 7088131 T ELEX #298949 LINN UR
-
+(818) 708-8131 TELEX #298949 LINN UR
+

tests/cache/cmyk/__-l__eng__000001.ocr.png__000001.text__pdf__txt/stderr.bin

@@ -1,2 +1 @@
-Tesseract Open Source OCR Engine v3.05.01 with Leptonica
-OSD: Weak margin (6.83) for 47 blob text block, but using orientation anyway: 0
+Tesseract Open Source OCR Engine v4.0.0 with Leptonica