v13.6.0 release notes

Unpaper or its underlying libraries don't seem to accept pnms with an
odd integer width. Although it's not clear if this is the issue at all.

In any case, keeping the image a PNG works around the issue. unpaper
only accepted PNM input in the past, which is why we send it PNM.
Since it now accepts PNG, we might as well use PNG.

Unpaper can write PNG as output too, but this added a few seconds to
the test suite was not committed.

Related issues:

https://github.com/ocrmypdf/OCRmyPDF/issues/887

https://github.com/ocrmypdf/OCRmyPDF/issues/665

https://github.com/unpaper/unpaper/issues/82

README.md

@@ -62,7 +62,8 @@ Linux, Windows, macOS and FreeBSD are supported. Docker images are also availabl
 | Debian, Ubuntu                | ``apt install ocrmypdf``      |
 | Windows Subsystem for Linux   | ``apt install ocrmypdf``      |
 | Fedora                        | ``dnf install ocrmypdf``      |
-| macOS                         | ``brew install ocrmypdf``     |
+| macOS (Homebrew)              | ``brew install ocrmypdf``     |
+| macOS (nix)                   | ``nix-env -i  ocrmypdf``      |
 | LinuxBrew                     | ``brew install ocrmypdf``     |
 | FreeBSD                       | ``pkg install py37-ocrmypdf`` |
 | Conda                         | ``conda install ocrmypdf``    |

docs/batch.rst

@@ -36,18 +36,21 @@ 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
+place, and printing each filename in between runs:
 
 .. code-block:: bash
 
-   find . -printf '%p' -name '*.pdf' -exec ocrmypdf '{}' '{}' \;
+   find . -printf '%p\n' -name '*.pdf' -exec ocrmypdf '{}' '{}' \;
 
-Alternatively, with a docker container (mounts a volume to the container
-where the PDFs are stored):
+Alternatively, with a Docker container and streaming the file through
+standard input and output:
 
 .. code-block:: bash
 
-   find . -printf '%p' -name '*.pdf' -exec docker run --rm -v <host dir>:<container dir> jbarlow83/ocrmypdf '<container dir>/{}' '<container dir>/{}' \;
+   find . -name '*.pdf' -print0 | xargs -0 | while read pdf; do
+       pdfout=$(mktemp)
+       docker run --rm -i jbarlow83/ocrmypdf - - <$pdf >$pdfout && cp $pdfout $pdf
+   done
 
 This only runs one ``ocrmypdf`` process at a time. This variation uses
 ``find`` to create a directory list and ``parallel`` to parallelize runs
@@ -124,7 +127,9 @@ Users may need to customize the script to meet their requirements.
 
     "OCR_INPUT_DIRECTORY", "Set input directory to monitor (recursive)"
     "OCR_OUTPUT_DIRECTORY", "Set output directory (should not be under input)"
+    "OCR_ARCHIVE_DIRECTORY", "Set archive directory for processed originals (should not be under input, requires ``OCR_ON_SUCCESS_ARCHIVE`` to be set)"
     "OCR_ON_SUCCESS_DELETE", "This will delete the input file if the exit code is 0 (OK)"
+    "OCR_ON_SUCCESS_ARCHIVE", "This will move the processed orignal file to ``OCR_ARCHIVE_DIRECTORY`` if the exit code is 0 (OK). Note that ``OCR_ON_SUCCESS_DELETE`` takes precedence over this option, i.e. if both options are set, the input file will be deleted."
     "OCR_OUTPUT_DIRECTORY_YEAR_MONTH", "This will place files in the output in ``{output}/{year}/{month}/{filename}``"
     "OCR_DESKEW", "Apply deskew to crooked input PDFs"
     "OCR_JSON_SETTINGS", "A JSON string specifying any other arguments for ``ocrmypdf.ocr``, e.g. ``'OCR_JSON_SETTINGS={""rotate_pages"": true}'``."
@@ -144,16 +149,18 @@ The watcher service is included in the OCRmyPDF Docker image. To run it:
     docker run \
         -v <path to files to convert>:/input \
         -v <path to store results>:/output \
+        -v <path to store processed originals>:/archive \
         -e OCR_OUTPUT_DIRECTORY_YEAR_MONTH=1 \
-        -e OCR_ON_SUCCESS_DELETE=1 \
+        -e OCR_ON_SUCCESS_ARCHIVE=1 \
         -e OCR_DESKEW=1 \
         -e PYTHONUNBUFFERED=1 \
         -it --entrypoint python3 \
         jbarlow83/ocrmypdf \
         watcher.py
 
-This service will watch for a file that matches ``/input/\*.pdf`` and will
-convert it to a OCRed PDF in ``/output/``. The parameters to this image are:
+This service will watch for a file that matches ``/input/\*.pdf``,
+convert it to a OCRed PDF in ``/output/``, and move the processed
+original to ``/archive``. The parameters to this image are:
 
 .. csv-table:: watcher.py parameters for Docker
     :header: "Parameter", "Description"
@@ -161,10 +168,11 @@ convert it to a OCRed PDF in ``/output/``. The parameters to this image are:
 
     "``-v <path to files to convert>:/input``", "Files placed in this location will be OCRed"
     "``-v <path to store results>:/output``", "This is where OCRed files will be stored"
-    "``-e OCR_OUTPUT_DIRECTORY_YEAR_MONTH=1``", "Define environment variable OCR_OUTPUT_DIRECTORY_YEAR_MONTH=1"
-    "``-e OCR_ON_SUCCESS_DELETE=1``", "Define environment variable"
-    "``-e OCR_DESKEW=1``", "Define environment variable"
-    "``-e PYTHONBUFFERED=1``", "This will force STDOUT to be unbuffered and allow you to see messages in docker logs"
+    "``-v <path to store processed originals>:/archive``", "Archive processed originals here"
+    "``-e OCR_OUTPUT_DIRECTORY_YEAR_MONTH=1``", "Define environment variable ``OCR_OUTPUT_DIRECTORY_YEAR_MONTH=1`` to place files in the output in ``{output}/{year}/{month}/{filename}``"
+    "``-e OCR_ON_SUCCESS_ARCHIVE=1``", "Define environment variable ``OCR_ON_SUCCESS_ARCHIVE`` to move processed originals"
+    "``-e OCR_DESKEW=1``", "Define environment variable ``OCR_DESKEW``  to apply deskew to crooked input PDFs"
+    "``-e PYTHONBUFFERED=1``", "This will force ``STDOUT`` to be unbuffered and allow you to see messages in docker logs"
 
 This service relies on polling to check for changes to the filesystem. It
 may not be suitable for some environments, such as filesystems shared on a

docs/cookbook.rst

@@ -200,7 +200,7 @@ might remove desirable content, especially from poor quality scans.
 
 .. warning::
 
-   ``--clean-final`` and ``-remove-background`` may leave undesirable
+   ``--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.

docs/release_notes.rst

@@ -24,10 +24,18 @@ tagged yet.
 
 .. |OCRmyPDF PyPI| image:: https://img.shields.io/pypi/v/ocrmypdf.svg
 
+v13.6.0
+=======
+
+-  Added a new ``initialize`` plugin hook, making it possible to suppress built-in
+   plugins more easily, among other possibilities.
+-  Fixed an issue where unpaper would exit with a "wrong stream" error, probably
+   related to images with an odd integer width. :issue:`887, 665`
+
 v13.5.0
 =======
 
--  Added a new ``optimize_pdf`` pluginhook, making it possible to create plugins that
+-  Added a new ``optimize_pdf`` plugin hook, making it possible to create plugins that
    replace or enhance OCRmyPDF's PDF optimizer.
 -  Removed all max version restrictions. Our new policy is to blacklist known-bad releases
    and only block known-bad versions of dependencies.

misc/watcher.py

@@ -23,6 +23,7 @@
 import json
 import logging
 import os
+import shutil
 import sys
 import time
 from datetime import datetime
@@ -44,8 +45,10 @@ def getenv_bool(name: str, default: str = 'False'):
 
 INPUT_DIRECTORY = os.getenv('OCR_INPUT_DIRECTORY', '/input')
 OUTPUT_DIRECTORY = os.getenv('OCR_OUTPUT_DIRECTORY', '/output')
+ARCHIVE_DIRECTORY = os.getenv('OCR_ARCHIVE_DIRECTORY', '/processed')
 OUTPUT_DIRECTORY_YEAR_MONTH = getenv_bool('OCR_OUTPUT_DIRECTORY_YEAR_MONTH')
 ON_SUCCESS_DELETE = getenv_bool('OCR_ON_SUCCESS_DELETE')
+ON_SUCCESS_ARCHIVE = getenv_bool('OCR_ON_SUCCESS_ARCHIVE')
 DESKEW = getenv_bool('OCR_DESKEW')
 OCR_JSON_SETTINGS = json.loads(os.getenv('OCR_JSON_SETTINGS', '{}'))
 POLL_NEW_FILE_SECONDS = int(os.getenv('OCR_POLL_NEW_FILE_SECONDS', '1'))
@@ -108,9 +111,13 @@ def execute_ocrmypdf(file_path):
         deskew=DESKEW,
         **OCR_JSON_SETTINGS,
     )
-    if exit_code == 0 and ON_SUCCESS_DELETE:
-        log.info(f'OCR is done. Deleting: {file_path}')
-        file_path.unlink()
+    if exit_code == 0:
+        if ON_SUCCESS_DELETE:
+            log.info(f'OCR is done. Deleting: {file_path}')
+            file_path.unlink()
+        elif ON_SUCCESS_ARCHIVE:
+            log.info(f'OCR is done. Archiving {file_path.name} to {ARCHIVE_DIRECTORY}')
+            shutil.move(file_path, f'{ARCHIVE_DIRECTORY}/{file_path.name}')
     else:
         log.info('OCR is done')
 
@@ -135,13 +142,16 @@ def main():
         f"Starting OCRmyPDF watcher with config:\n"
         f"Input Directory: {INPUT_DIRECTORY}\n"
         f"Output Directory: {OUTPUT_DIRECTORY}\n"
-        f"Output Directory Year & Month: {OUTPUT_DIRECTORY_YEAR_MONTH}"
+        f"Output Directory Year & Month: {OUTPUT_DIRECTORY_YEAR_MONTH}\n"
+        f"Archive Directory: {ARCHIVE_DIRECTORY}"
     )
     log.debug(
         f"INPUT_DIRECTORY: {INPUT_DIRECTORY}\n"
         f"OUTPUT_DIRECTORY: {OUTPUT_DIRECTORY}\n"
         f"OUTPUT_DIRECTORY_YEAR_MONTH: {OUTPUT_DIRECTORY_YEAR_MONTH}\n"
+        f"ARCHIVE_DIRECTORY: {ARCHIVE_DIRECTORY}\n"
         f"ON_SUCCESS_DELETE: {ON_SUCCESS_DELETE}\n"
+        f"ON_SUCCESS_ARCHIVE: {ON_SUCCESS_ARCHIVE}\n"
         f"DESKEW: {DESKEW}\n"
         f"ARGS: {OCR_JSON_SETTINGS}\n"
         f"POLL_NEW_FILE_SECONDS: {POLL_NEW_FILE_SECONDS}\n"

src/ocrmypdf/_exec/unpaper.py

@@ -72,13 +72,13 @@ def version() -> str:
     return get_version('unpaper')
 
 
-SUFFIXES = {'1': '.pbm', 'L': '.pgm', 'RGB': '.ppm'}
+SUPPORTED_MODES = {'1', 'L', 'RGB'}
 
 
-def _convert_image(im: Image.Image) -> Tuple[Image.Image, bool, str]:
+def _convert_image(im: Image.Image) -> Tuple[Image.Image, bool]:
     im_modified = False
 
-    if im.mode not in SUFFIXES:
+    if im.mode not in SUPPORTED_MODES:
         log.info("Converting image to other colorspace")
         try:
             if im.mode == 'P' and len(im.getcolors()) == 2:
@@ -91,13 +91,11 @@ def _convert_image(im: Image.Image) -> Tuple[Image.Image, bool, str]:
             ) from e
         else:
             im_modified = True
-    try:
-        suffix = SUFFIXES[im.mode]
-    except KeyError:
-        raise MissingDependencyError(
-            "Failed to convert image to a supported format."
-        ) from None
-    return im, im_modified, suffix
+        if im.mode not in SUPPORTED_MODES:
+            raise MissingDependencyError(
+                "Failed to convert image to a supported format."
+            ) from None
+    return im, im_modified
 
 
 @contextmanager
@@ -105,19 +103,21 @@ def _setup_unpaper_io(input_file: Path) -> Iterator[Tuple[Path, Path, Path]]:
     with Image.open(input_file) as im:
         if im.width * im.height >= UNPAPER_IMAGE_PIXEL_LIMIT:
             raise UnpaperImageTooLargeError(w=im.width, h=im.height)
-        im, im_modified, suffix = _convert_image(im)
+        im, im_modified = _convert_image(im)
 
         with TemporaryDirectory(ignore_cleanup_errors=True) as tmpdir:
             tmppath = Path(tmpdir)
-            if im_modified or input_file.suffix != '.pnm':
-                input_pnm = tmppath / 'input.pnm'
-                im.save(input_pnm, format='PPM')
+            if im_modified or input_file.suffix != '.png':
+                input_png = tmppath / 'input.png'
+                im.save(input_png, format='PNG')
             else:
                 # No changes, PNG input, just use the file we already have
-                input_pnm = input_file
+                input_png = input_file
 
-            output_pnm = tmppath / f'output{suffix}'
-            yield input_pnm, output_pnm, tmppath
+            # unpaper can write .png too, but it seems to write them slowly
+            # adds a few seconds to test suite - so just use pnm
+            output_pnm = tmppath / 'output.pnm'
+            yield input_png, output_pnm, tmppath
 
 
 def run_unpaper(
@@ -125,7 +125,7 @@ def run_unpaper(
 ) -> None:
     args_unpaper = ['unpaper', '-v', '--dpi', str(round(dpi, 6))] + mode_args
 
-    with _setup_unpaper_io(input_file) as (input_pnm, output_pnm, tmpdir):
+    with _setup_unpaper_io(input_file) as (input_png, output_pnm, tmpdir):
         # 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
@@ -133,7 +133,7 @@ def run_unpaper(
         # 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([os.fspath(input_pnm), os.fspath(output_pnm)])
+        args_unpaper.extend([os.fspath(input_png), os.fspath(output_pnm)])
         run(
             args_unpaper,
             close_fds=True,

src/ocrmypdf/_plugin_manager.py

@@ -116,6 +116,9 @@ def get_parser_options_plugins(
     plugin_manager = get_plugin_manager(pre_options.plugins)
 
     parser = get_parser()
+    plugin_manager.hook.initialize(  # pylint: disable=no-member
+        plugin_manager=plugin_manager
+    )
     plugin_manager.hook.add_options(parser=parser)  # pylint: disable=no-member
 
     options = parser.parse_args(args=args)

src/ocrmypdf/builtin_plugins/optimize.py

@@ -12,8 +12,7 @@ import logging
 from pathlib import Path
 from typing import Sequence, Tuple
 
-from ocrmypdf import PdfContext, hookimpl
-from ocrmypdf._concurrent import Executor
+from ocrmypdf import Executor, PdfContext, hookimpl
 from ocrmypdf._exec import jbig2enc, pngquant
 from ocrmypdf._pipeline import get_pdf_save_settings
 from ocrmypdf.cli import numeric

src/ocrmypdf/pluginspec.py

@@ -22,8 +22,7 @@ from typing import (
 
 import pluggy
 
-from ocrmypdf import PdfContext
-from ocrmypdf._concurrent import Executor
+from ocrmypdf import Executor, PdfContext
 from ocrmypdf.helpers import Resolution
 
 if TYPE_CHECKING:
@@ -52,6 +51,33 @@ def get_logging_console() -> Handler:
     """
 
 
+@hookspec
+def initialize(plugin_manager: pluggy.PluginManager):
+    """Called when this plugin is first loaded into OCRmyPDF.
+
+    The primary intended use of this is for plugins to check compatibility with other
+    plugins and possibly block other blocks, a plugin that wishes to block ocrmypdf's
+    built-in optimize plugin could do:
+
+    .. code-block::
+
+        plugin_manager.set_blocked('ocrmypdf.builtin_plugins.optimize')
+
+    It would also be reasonable for an plugin implementation to check if it is unable
+    to proceed, for example, because a required dependency is missing. (If the plugin's
+    ability to proceed depends on options and arguments, use ``validate`` instead.)
+
+    Raises:
+        ocrmypdf.exceptions.ExitCodeException: If options are not acceptable
+            and the application should terminate gracefully with an informative
+            message and error code.
+
+    Note:
+        This hook will be called from the main process, and may modify global state
+        before child worker processes are forked.
+    """
+
+
 @hookspec
 def add_options(parser: ArgumentParser) -> None:
     """Allows the plugin to add its own command line and API arguments.
@@ -484,6 +510,9 @@ def optimize_pdf(
     If the implementation fails to produce a smaller file than the input file, it
     should return input_pdf instead.
 
+    A plugin that implements a new optimizer may need to suppress the built-in
+    optimizer by implementing an ``initialize`` hook.
+
     Arguments:
         input_pdf: The input PDF, which has OCR added.
         output_pdf: The requested filename of the output PDF which should be created
@@ -512,8 +541,8 @@ def optimize_pdf(
 def is_optimization_enabled(context: PdfContext) -> bool:
     """For a given PdfContext, OCRmyPDF asks the plugin if optimization is enabled.
 
-    It is assumed that an optimization plugin might be installed but could be
-    disabled by user settings.
+    An optimization plugin might be installed and active but could be disabled by
+    user settings.
 
     If this returns False, OCRmyPDF will take certain actions to finalize the PDF.
 

tests/cache/francais/__-l__deu__000001_ocr.png__000001_ocr_tess__pdf__txt/stderr.bin

@@ -0,0 +1 @@
+Tesseract Open Source OCR Engine v4.1.1 with Leptonica

tests/cache/francais/__-l__deu__000001_ocr.png__000001_ocr_tess__pdf__txt/txt.bin

@@ -0,0 +1,13 @@
+Portez ce vieux whisky au juge
+blond qui fume sur son Ile
+interieure, a cöte de l'alcöve
+ovoide, oU les büches se
+consument dans l'ätre, ce qui
+lui permet de penser & la
+caenogenese de |'etre dont il
+est question dans la cause
+ambigu& entendue a MoY, dans
+un capharnaüm qui, pense-t-il,
+diminue ca et la la qualite de son
+ceuvre.
+

tests/cache/manifest.jsonl

@@ -82,3 +82,4 @@
 {"tesseract_version": "4.1.1", "system": "Linux", "python": "3.9.5", "argv_slug": "__-l__eng__--oem__1__000001_ocr.png__000001_ocr_tess__pdf__txt", "sourcefile": "resources/trivial.pdf", "args": ["-l", "eng", "--oem", "1", "-c", "textonly_pdf=1", "$TMPDIR/000001_ocr.png", "$TMPDIR/000001_ocr_tess", "pdf", "txt"]}
 {"tesseract_version": "5.0.0", "system": "Linux", "python": "3.9.5", "argv_slug": "__-l__eng__thresholding_method=1__000001_ocr.png__000001_ocr_tess__pdf__txt", "sourcefile": "resources/trivial.pdf", "args": ["-l", "eng", "-c", "textonly_pdf=1", "-c", "thresholding_method=1", "$TMPDIR/000001_ocr.png", "$TMPDIR/000001_ocr_tess", "pdf", "txt"]}
 {"tesseract_version": "5.0.0", "system": "Linux", "python": "3.9.5", "argv_slug": "__-l__eng__thresholding_method=2__000001_ocr.png__000001_ocr_tess__pdf__txt", "sourcefile": "resources/trivial.pdf", "args": ["-l", "eng", "-c", "textonly_pdf=1", "-c", "thresholding_method=2", "$TMPDIR/000001_ocr.png", "$TMPDIR/000001_ocr_tess", "pdf", "txt"]}
+{"tesseract_version": "4.1.1", "system": "Linux", "python": "3.10.4", "argv_slug": "__-l__deu__000001_ocr.png__000001_ocr_tess__pdf__txt", "sourcefile": "resources/francais.pdf", "args": ["-l", "deu", "-c", "textonly_pdf=1", "$TMPDIR/000001_ocr.png", "$TMPDIR/000001_ocr_tess", "pdf", "txt"]}

tests/test_pdfinfo.py

@@ -24,20 +24,24 @@ from ocrmypdf.pdfinfo.layout import PDFPage
 # pylint: disable=protected-access
 
 
-def test_single_page_text(outdir):
+@pytest.fixture
+def single_page_text(outdir):
     filename = outdir / 'text.pdf'
     pdf = Canvas(str(filename), pagesize=(8 * inch, 6 * inch))
     text = pdf.beginText()
     text.setFont('Helvetica', 12)
     text.setTextOrigin(1 * inch, 3 * inch)
     text.textLine(
-        "Methink'st thou art a general offence and every" " man should beat thee."
+        "Methink'st thou art a general offence and every man should beat thee."
     )
     pdf.drawText(text)
     pdf.showPage()
     pdf.save()
+    return filename
 
-    info = pdfinfo.PdfInfo(filename)
+
+def test_single_page_text(single_page_text):
+    info = pdfinfo.PdfInfo(single_page_text)
 
     assert len(info) == 1
     page = info[0]
@@ -54,7 +58,8 @@ def eight_by_eight():
     return im
 
 
-def test_single_page_image(eight_by_eight, outpdf):
+@pytest.fixture
+def eight_by_eight_regular_image(eight_by_eight, outpdf):
     im = eight_by_eight
     bio = BytesIO()
     im.save(bio, format='PNG')
@@ -71,7 +76,11 @@ def test_single_page_image(eight_by_eight, outpdf):
             outputstream=f,
             **IMG2PDF_KWARGS,
         )
-    info = pdfinfo.PdfInfo(outpdf)
+    return outpdf
+
+
+def test_single_page_image(eight_by_eight_regular_image):
+    info = pdfinfo.PdfInfo(eight_by_eight_regular_image)
 
     assert len(info) == 1
     page = info[0]
@@ -88,16 +97,18 @@ def test_single_page_image(eight_by_eight, outpdf):
     assert isclose(pdfimage.dpi.y, 8)
 
 
-def test_single_page_inline_image(eight_by_eight, outdir):
-    filename = outdir / 'image-mono-inline.pdf'
-    pdf = Canvas(str(filename), pagesize=(8 * 72, 6 * 72))
-
+@pytest.fixture
+def eight_by_eight_inline_image(eight_by_eight, outpdf):
+    pdf = Canvas(str(outpdf), pagesize=(8 * 72, 6 * 72))
     # Draw image in a 72x72 pt or 1"x1" area
     pdf.drawInlineImage(eight_by_eight, 0, 0, width=72, height=72)
     pdf.showPage()
     pdf.save()
+    return outpdf
 
-    info = pdfinfo.PdfInfo(filename)
+
+def test_single_page_inline_image(eight_by_eight_inline_image):
+    info = pdfinfo.PdfInfo(eight_by_eight_inline_image)
     print(info)
     pdfimage = info[0].images[0]
     assert isclose(pdfimage.dpi.x, 8)
@@ -177,7 +188,7 @@ def test_stack_abuse():
         pdfinfo.info._interpret_contents(stream)
 
     stream = pikepdf.Stream(p, b'q Q Q Q Q')
-    with pytest.warns(UserWarning, match="underflowed") as record:
+    with pytest.warns(UserWarning, match="underflowed"):
         pdfinfo.info._interpret_contents(stream)
 
     stream = pikepdf.Stream(p, b'q ' * 135)
@@ -201,7 +212,8 @@ def test_pages_issue700(monkeypatch, resources):
         )
 
 
-def test_image_scale0(resources, outpdf):
+@pytest.fixture
+def image_scale0(resources, outpdf):
     with pikepdf.open(resources / 'cmyk.pdf') as cmyk:
         xobj = cmyk.pages[0].as_form_xobject()
 
@@ -215,7 +227,12 @@ def test_image_scale0(resources, outpdf):
             p, b"q 0 0 0 0 0 0 cm %s Do Q" % bytes(objname)
         )
         p.save(outpdf)
+    return outpdf
 
-    pi = pdfinfo.PdfInfo(outpdf, detailed_analysis=True, progbar=False, max_workers=1)
+
+def test_image_scale0(image_scale0):
+    pi = pdfinfo.PdfInfo(
+        image_scale0, detailed_analysis=True, progbar=False, max_workers=1
+    )
     assert not pi.pages[0]._images[0].dpi.is_finite
     assert pi.pages[0].dpi == Resolution(0, 0)