James R. Barlow
12ec97f732
Resolves the last 16 mypy errors in the project (src/ocrmypdf and
tests are now fully clean).
fpdf_renderer/renderer.py (9 errors):
- add_page(format=...): fpdf2's own stub types this param as str, but
its docstring and get_page_format() helper confirm a (width, height)
tuple is accepted too - the stub annotation on add_page() itself is
the outlier. Used cast() to match the documented/actual behavior.
- pdf.current_font is typed CoreFont | TTFFont | None, but this
renderer only ever registers fonts via add_font() with a TTF file
(see _register_font/set_font call sites) - it never falls back to
fpdf2's built-in CoreFont. Added assertions (isinstance(font,
TTFFont) where shape_text()/escape_text() are needed, which
CoreFont lacks; plain not-None elsewhere) documenting that
invariant instead of narrowing defensively for a case that can't
happen here.
tests/test_pdf_renderer.py (7 errors): the ToUnicode/glyph-extraction
test helpers used `.get(key, {})` (a plain dict literal default) then
called `.values()`/`.items()` on the result. pikepdf.Object doesn't
declare `values()` in its stub (only `keys()`), so this silently
degraded to Object's catch-all `__getattr__` returning another Object,
which then failed as "not callable". Switched to `.get(key,
Dictionary()).as_dict()`, which returns pikepdf's properly-typed
_ObjectMapping helper.
OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to be searched or copy-pasted.
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.
Main features
- Generates a searchable 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 engine to recognize more than 100 languages
- Keeps your private data private.
- Scales properly to handle files with thousands of pages.
- Battle-tested on millions of PDFs.
For details: please consult the documentation.
Motivation
I searched the web for a free command line tool to OCR PDF files: 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, Windows, macOS and FreeBSD are supported. Docker images are also available, for both x64 and ARM.
| Operating system | Install command |
|---|---|
| Debian, Ubuntu | apt install ocrmypdf |
| Windows Subsystem for Linux | apt install ocrmypdf |
| Fedora | dnf install ocrmypdf |
| macOS (Homebrew) | brew install ocrmypdf |
| macOS (MacPorts) | port install ocrmypdf |
| macOS (nix) | nix-env -i ocrmypdf |
| LinuxBrew | brew install ocrmypdf |
| FreeBSD | pkg install py-ocrmypdf |
| OpenBSD | pkg_add ocrmypdf |
| Ubuntu Snap | snap install ocrmypdf |
For everyone else, see our documentation 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:
# Debian/Ubuntu users
apt-cache search tesseract-ocr # Display a list of all Tesseract language packs
apt-get install tesseract-ocr-chi-sim # Example: Install Chinese Simplified language pack
# Arch Linux users
pacman -S tesseract-data-eng tesseract-data-deu # Example: Install the English and German language packs
# OpenBSD users
pkg_info -aQ tesseract # Display a list of all Tesseract language packs
pkg_add tesseract-cym # Example: Install the Welsh language pack
# brew macOS users
brew install tesseract-lang
# Fedora users
dnf search tesseract-langpack # Display a list of all Tesseract language packs
dnf install tesseract-langpack-ita # Example: Install the Italian language pack
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.
OCRmyPDF supports Tesseract 4.1.1+. It will automatically use whichever version it finds first on the PATH environment variable. On Windows, if PATH does not provide a Tesseract binary, we use the highest version number that is installed according to the Windows Registry.
Documentation and support
Once OCRmyPDF is installed, the built-in help which explains the command syntax and options can be accessed via:
ocrmypdf --help
Our documentation is served on Read the Docs.
Please report issues on our GitHub issues page, and follow the issue template for quick response.
Feature demo
# Add an OCR layer and require PDF/A
ocrmypdf --output-type pdfa input.pdf output.pdf
# Convert an image to single page PDF
ocrmypdf input.jpg output.pdf
# Add OCR to a file in place (only modifies file on success)
ocrmypdf myfile.pdf myfile.pdf
# OCR with non-English languages (look up your language's ISO 639-3 code)
ocrmypdf -l fra LeParisien.pdf LeParisien.pdf
# OCR multilingual documents
ocrmypdf -l eng+fra Bilingual-English-French.pdf Bilingual-English-French.pdf
# Deskew (straighten crooked pages)
ocrmypdf --deskew input.pdf output.pdf
For more features, see the documentation.
Requirements
In addition to the required Python version, OCRmyPDF requires external program installations of Ghostscript and Tesseract OCR. OCRmyPDF is pure Python, and runs on pretty much everything: Linux, macOS, Windows and FreeBSD.
Plugins
OCRmyPDF provides a plugin interface allowing its capabilities to be extended or replaced. Here are some plugins we are aware of:
- OCRmyPDF-AppleOCR: replaces the standard Tesseract OCR engine with Apple Vision Framework. Requires macOS.
- OCRmyPDF-EasyOCR: replaces the standard Tesseract OCR engine with EasyOCR, a newer OCR engine based on PyTorch. GPU strongly recommended.
- OCRmyPDF-PaddleOCR: replaces the standard Tesseract OCR engine with PaddleOCR, a powerful GPU accelerated OCR engine.
paperless-ngx provides integration of OCRmyPDF into a searchable document management system.
Press & Media
- Going paperless with OCRmyPDF
- Converting a scanned document into a compressed searchable PDF with redactions
- c't 1-2014, page 59: Detailed presentation of OCRmyPDF v1.0 in the leading German IT magazine c't
- heise Open Source, 09/2014: Texterkennung mit OCRmyPDF
- heise Durchsuchbare PDF-Dokumente mit OCRmyPDF erstellen
- Excellent Utilities: OCRmyPDF
- LinuxUser Texterkennung mit OCRmyPDF und Scanbd automatisieren
- Y Combinator discussion
Business enquiries
OCRmyPDF would not be the software that it is today without companies and users choosing to provide support for feature development and consulting enquiries. We are happy to discuss all enquiries, whether for extending the existing feature set, or integrating OCRmyPDF into a larger system.
License
The OCRmyPDF software is licensed under the Mozilla Public License 2.0 (MPL-2.0). This license permits integration of OCRmyPDF with other code, included commercial and closed source, but asks you to publish source-level modifications you make to OCRmyPDF.
Some components of OCRmyPDF have other licenses, as indicated by standard SPDX license identifiers or the DEP5 copyright and licensing information file. Generally speaking, non-core code is licensed under MIT, and the documentation and test files are licensed under Creative Commons ShareAlike 4.0 (CC-BY-SA 4.0).
Disclaimer
The software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.