Release notes

OCRmyPDF uses semantic versioning for its command line interface and its public API.

OCRmyPDF’s output messages are not considered part of the stable interface - that is, output messages may be improved at any release level, so parsing them may be unreliable. Use the API to depend on precise behavior.

The public API may be useful in scripts that launch OCRmyPDF processes or that wish to use some of its features for working with PDFs.

The most recent release of OCRmyPDF is OCRmyPDF PyPI. Any newer versions referred to in these notes may exist the main branch but have not been tagged yet.

OCRmyPDF typically supports the three most recent Python versions.


Attention maintainers: these release notes may be updated with information about a forthcoming release that has not been tagged yet. A release is only official when it’s tagged and posted to PyPI.


  • Fixed some issues for left-to-right text with the new hOCR renderer. It is still not default yet but will be made so soon. Right-to-left text is still in progress.

  • Added an error to prevent use of several versions of Ghostscript that seem corrupt existing text in input PDFs. Newly generated OCR is not affected. For best results, use Ghostscript 10.02.1 or newer, which contains the fix for the issue.


  • Changed minimum required Ghostscript to 9.54, to support users of RHEL 9 and its derivatives, since that is the latest version available there.

  • Removed warning message about CVE-2023-43115, on the assumption that most distributions have backported the patch by now.


  • Temporarily changed PDF text renderer back to sandwich by default to address regressions in macOS Preview.


  • Fixed text rendering issue with new hOCR text renderer - extraneous byte order marks.

  • Tightened dependencies.


  • Added OCR text renderer, combined the best ideas of Tesseract’s PDF generator and the older hOCR transformer renderer. The result is a hopefully permanent fix for wordssmushedtogetherwithoutspaces issues in extracted text, better registration/position of text on skewed baselines #1009, fixes to character output when the German Fraktur script is used #1191, proper rendering of right to left languages (Arabic, Hebrew, Persian) #1157. Asian languages may still have excessive word breaks compared to expectations. The new renderer is the default; the old sandwich renderer is still available using --pdf-renderer sandwich; the old hOCR renderer is no more.

  • The ocrmypdf.hocrtransform API has changed substantially.

  • Support for Python 3.9 has been dropped. Python 3.10+ is now required.

  • pikepdf >= 8.8.0 is now required.


  • Fixed documentation for installing Ghostscript on Windows. #1198

  • Added warning message about security issue in older versions of Ghostscript.


  • Fixed deprecation warning in pikepdf older than 8.7.1; pikepdf >= 8.7.1 is now required.


  • We now raise an exception on a certain class of PDFs that likely need an explicit color conversion strategy selected to display correctly for PDF/A conversion.

  • Fixed an error that occurred while trying to write a log message after the debug log handler was removed.


  • Fixed misc/ regressions: accept --ocr-json-settings as either filename or JSON string, as previously; and argument count mismatch. #1183, #1185

  • We no longer attempt to set /ProcSet in the PDF output, since this is an obsolete PDF feature.

  • Documentation improvements.


  • Added new experimental APIs to support offline editing of the final text. Specifically, one can now generate hOCR files with OCRmyPDF, edit them with some other tool, and then finalize the PDF. They are experimental and subject to change, including details of how the working folder is used. There is no command line interface.

  • Code reorganization: executors, progress bars, initialization and setup.

  • Fixed test coverage in cases where the coverage tool did not properly trace into threads or subprocesses. This code was still being tested but appeared as not covered.

  • In the test suite, reduced use of subprocesses and other techniques that interfere with coverage measurement.

  • Improved error check for when we appear to be running inside a snap container and files are not available.

  • Plugin specification now properly defines progress bars as a protocol rather than defining them as “tqdm-like”.

  • We now default to using “forkserver” process creation on POSIX platforms rather than fork, since this is method is more robust and avoids some issues when threads are present.

  • Fixed an instance where the user’s request to --no-use-threads was ignored.

  • If a PDF does not have language metadata on its top level object, we add the OCR language.

  • Replace some cryptic test error messages with more helpful ones.

  • Debug messages for how OCRmyPDF picks the colorspace for a page are now more descriptive.


  • Fixed an issue with logging settings for misc/ introduced in the previous release. #1180

  • We now attempt to preserve the input’s extended attributes when creating the output file.

  • For some reason, the macOS build now needs OpenSSL explicitly installed.

  • Updated documentation on Docker performance concerns.


  • Update misc/ to improve command line interface using Typer, and support .env specification of environment variables. Improved error messages. Thanks to @mflagg2814 for the PR that prompted this improvement.

  • Improved error message when a file cannot be read because we are running in a snap container.


  • Added a Docker image based on Alpine Linux. This image is smaller than the Ubuntu-based image and may be useful in some situations. Currently hosted at jbarlow83/ocrmypdf-alpine. Currently not available in ARM flavor.

  • The Ubuntu Docker is now aliased to jbarlow83/ocrmypdf-ubuntu.

  • Updated Docker documentation.


  • We now require Pillow 10.0.1, due a serious security vulnerability in all earlier versions of that dependency. The vulnerability concerns WebP images and could be triggered in OCRmyPDF when creating a PDF from a malicious WebP image.

  • Added some keyword arguments to ocrmypdf.ocr that were previously accepted but undocumented.

  • Documentation updates and typing improvements.


  • Added Python 3.12 to test matrix.

  • Updated documentation for notes on Python 3.12, 32-bit support and some new features in v15.


  • Wheels Python tag changed to py39.

  • Marked as a expected fail a test that fails on recent Ghostscript versions.

  • Clarified documentation and release notes around the extent of 32-bit support.

  • Updated installation documentation to changes in v15.


  • Dropped support for Python 3.8.

  • Dropped support some older dependencies, specifically coloredlogs and tqdm in favor of rich - see pyproject.toml for details. Generally speaking, Ubuntu 22.04 is our new baseline system.

  • Tightened version requirements for some dependencies.

  • Dropped support for 32-bit Linux wheels. We strongly recommend a 64-bit operating system, and 64-bit versions of Python, Tesseract and Ghostscript to use OCRmyPDF. Many of our dependencies are dropping 32-bit builds (e.g. Pillow), and we are following suit. (Maintainers may still build 32-bit versions from source.)

  • Changed to trusted release for PyPI publishing.

  • pikepdf memory mapping is enabled again for improved performance, now that an issue with feature in pikepdf is fixed.

  • ocrmypdf.helpers.calculate_downsample previously had two variants, one that took a PIL.Image and one that took a tuple[int, int]. The latter was removed.

  • The snap version of ocrmypdf is now based on Ubuntu core22.

  • We now account for situations where a small portion of an image on a page is drawn at high DPI (resolution). Previously, the entire page would be rasterized at the highest resolution of any feature, which caused performance problems. Now, the page is rasterized at a resolution based on the average DPI of the page, weighted by the area that each feature occupies. Typically, small areas of high resolution in PDFs are errors or quirks from the repeated use of assets and high resolution is not beneficial. #1010, #1104, #1004, #1079, #1010

  • Ghostscript color conversion strategy is now configurable using --color-conversion-strategy. #1143

  • JBIG2 threshold for optimization is now configurable using --jbig2-threshold. #1133


  • Digitally signed PDFs are now detected. If the PDF is signed, OCRmyPDF will refuse to modify it. Previously, only encrypted PDFs were detected, not those that were signed but not encrypted. #1040

  • In addition, --invalidate-digital-signatures can be used to override the above behavior and modify the PDF anyway. #1040

  • tqdm progress bars replaced with “rich” progress bars. The rich library is a new dependency. Certain APIs that used tqdm are now deprecated and will be removed in the next major release.

  • Improved integration with GitHub Releases. Thanks to @stumpylog.


  • Renamed master branch to main.

  • Improve PDF rasterization accuracy by using the -dPDFSTOPONERROR option to Ghostscript. Use --continue-on-soft-render-error if you want to render the PDF anyway. The plugin specification was adjusted to support this feature; plugin authors may want to adapt PDF rasterizing and rendering plugins. #1083

  • The calculated deskew angle is now recorded in the logged output. #1101

  • Metadata can now be unset by setting a metadata type such as --title to an empty string. #1117, #1059

  • Fixed random order of languages due to use of a set. This may have caused output to vary when multiple languages were set for OCR. #1113

  • Clarified the optimization ratio reported in the log output.

  • Documentation improvements.


  • Fixed #977, where images inside Form XObjects were always excluded from image optimization.


  • Added --tesseract-downsample-above to downsample larger images even when they do not exceed Tesseract’s internal limits. This can be used to speed up OCR, possibly sacrificing accuracy.

  • Fixed resampling AttributeError on older Pillow. #1096

  • Removed an error about using Ghostscript on PDFs with that have the /UserUnit feature in use. Previously, Ghostscript would fail to process these PDFs, but in all supported versions it is now supported, so the error is no longer needed.

  • Improved documentation around installing other language packs for Tesseract.


  • Added --tesseract-non-ocr-timeout. This allows using Tesseract’s deskew and other non-OCR features while disabling OCR using --tesseract-timeout 0.

  • Added --tesseract-downsample-large-images. This downsamples larges images that exceed the maximum image size Tesseract can handle. Large images may still take a long time to process, but this allows them to be processed if that is desired.

  • Fixed #1082, an issue with snap packaged building.

  • Change linter to ruff, fix lint errors, update documentation.


  • Fixed #1066, #1075, an exception when processing certain malformed PDFs.


  • Fixed #1068, avoid deleting /dev/null when running as root.

  • Other documentation fixes.


  • Fixed #1052, an exception on attempting to process certain nonconforming PDFs.

  • Explicitly documented that Windows 32-bit is no longer supported.

  • Fixed source installation instructions.

  • Other documentation fixes.


  • Fixed some version checks done with smart version comparison.

  • Added missing jbig2dec to Docker image.


  • Dropped support for Python 3.7.

  • Dropped support generally speaking, all dependencies older than what Ubuntu 20.04 provides.

  • Ghostscript 9.50 or newer is now required. Shims to support old versions were removed.

  • Tesseract 4.1.1 or newer is now required. Shims to support old versions were removed.

  • Docker image now uses Tesseract 5.

  • Dropped setup.cfg configuration for pyproject.toml.

  • Removed deprecation exception PdfMergeFailedError.

  • A few more public domain test files were removed or replaced. We are aiming for 100% compliance with SPDX and generally towards simplifying copyright.


  • Fixed an exception when attempting to run and Tesseract is not installed.

  • Changed to SPDX license tracking and information files.


  • Added a shim to prevent an “error during error handling” for Python 3.7 and 3.8.

  • Modernized some type annotations.

  • Improved annotations on our _windows module to help IDEs and mypy figure out what we’re doing.


  • Require setuptools-scm 7.0.5 to avoid possible issues with source distributions in earlier versions of setuptools-scm.

  • Suppress a spurious warning, improve tests, improve typing and other miscellany.


  • 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. #887, #665


  • 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.

  • The naming schema for object that holds all OCR text that OCRmyPDF inserts has changed. This has always been an implementation detail (and remains so), but possibly, someone was relying on it and would appreciate the heads-up.

  • Cleanup.


  • Fixed PermissionError when cleaning up temporary files in rare cases. #974

  • Fixed PermissionError when calling os.nice on platforms that lack it. #973

  • Suppressed some warnings from libxmp during tests.


  • Convert error on corrupt ICC profiles into a warning. Thanks to @oscherler.


  • Remove upper bound on pdfminer.six version.

  • Documentation.


  • Updated pdfminer.six version.

  • Docker image changed to Ubuntu 22.04 now that it is released and provides the dependencies we need. This seems more consistent than our recent change to Debian.


  • Fix error on pytest.skip() with older versions of pytest.

  • Documentation updates.


  • Worked around a major regression in Ghostscript 9.56.0 where all OCR text is stripped out of the PDF. It simply removes all text, even generated by software other than OCRmyPDF. Fortunately, we can ask Ghostscript 9.56.0 to use its old behavior that worked correctly for our purposes. Users must avoid the combination (Ghostscript 9.56.0, ocrmypdf <13.4.2) since older versions of OCRmyPDF have no way of detecting that this particular version of Ghostscript removes all OCR text.

  • Marked pdfminer 20220319 as supported.

  • Fixed some deprecation warnings from recent versions of Pillow and pytest.

  • Test suite now covers Python 3.10 (Python 3.10 worked fine before, but was not being tested).

  • Docker image now uses debian:bookworm-slim as the base image to fix the Docker image build.


  • Temporarily make threads rather than processes the default executor worker, due to a persistent deadlock issue when processes are used. Add a new command line argument --no-use-threads to disable this.


  • Fixed test failures when using pikepdf 5.0.0.

  • Various improvements to the optimizer. In particular, we now recognize PDF images that are encoded with both deflate (PNG) and DCT (JPEG), and also produce PDF with images compressed with deflate and DCT, since this often yields file size improvements compared to plain DCT.


  • Made a harmless but “scary” exception after failing to optimize an image less scary.

  • Added a warning if a page image is too large for unpaper to clean. The image is passed through without cleaning. This is due to a hard-coded limitation in a C library used by unpaper so it cannot be rectified easily.

  • We now use better default settings when calling img2pdf.

  • We no longer try to optimize images that we failed to save in certain situations.

  • We now account for some differences in text output from Tesseract 5 compared to Tesseract 4.

  • Better handling of Ghostscript producing empty images when attempting to rasterize page images.


  • Removed all runtime uses of distutils since it is deprecated in standard library. We previous used distutils.version to examine version numbers of dependencies at run time, and now use packaging.version for this. This is a new dependency.

  • Fixed an error message advising the user that Ghostscript was not installed being suppressed when this condition actually happens.

  • Fixed an issue with incorrect page number and totals being displayed in the progress bar. This was purely a display/presentation issue. #876.


  • Fixed issue with attempting to deskew a blank page on Tesseract 5. #868.


  • Changed to using Python concurrent.futures-based parallel execution instead of pools, since futures have now exceed pools in features.

  • If a child worker is terminated (perhaps by the operating system or the user killing it in a task manager), the parallel task will fail an error message. Previously, the main ocrmypdf process would “hang” indefinitely, waiting for the child to report.

  • Added new argument --tesseract-thresholding to provide control over Tesseract 5’s threshold parameter.

  • Documentation updates and changes. Better documentation for --output-type none, added a few releases ago. Removed some obsolete documentation.

  • Improved bash completions - thanks to @FPille.


Breaking changes

  • The deprecated module ocrmypdf.leptonica has been removed.

  • We no longer depend on Leptonica (liblept) or CFFI (libffi, python3-cffi). (Note that Tesseract still requires Leptonica; OCRmyPDF no longer directly uses this library.)

  • The argument --remove-background is temporarily disabled while we search for an alternative to the Leptonica implementation of this feature.

  • The --threshold argument has been removed, since this also depended on Leptonica. Tesseract 5.x has implemented improvements to thresholding, so this feature will be redundant anyway.

  • --deskew was previous calculated by a Leptonica algorithm. We now use a feature of Tesseract to find the appropriate the angle to deskew a page. The deskew angle according to Tesseract may differ from Leptonica’s algorithm. At least in theory, Tesseract’s deskew angle is informed by a more complex analysis than Leptonica, so this should improve results in general. We also use Pillow to perform the deskewing, which may affect the appearance of the image compared to Leptonica.

  • Support for Python 3.6 was dropped, since this release is approaching end of life.

  • We now require pikepdf 4.0 or newer. This, in turn, means that OCRmyPDF requires a system compatible with the manylinux2014 specification. This change was “forced” by Pillow not releasing manylinux2010 wheels anymore.

  • We no longer provide requirements.txt-style files. Use pip install ocrmypdf[...] instead.

  • Bumped required versions of several libraries.


  • Fixed an issue where OCRmyPDF failed to find Ghostscript on Windows even when installed, and would exit with an error.

  • By removing Leptonica, we fixed all issues related to Leptonica on Apple Silicon or Leptonica failing to import on Windows.


  • Fixed “invalid version number” error for Tesseract packaging with nonstandard version “5.0.0-rc1.20211030”.

  • Fixed use of deprecated importlib.resources.read_binary.

  • Replace some uses of string paths with pathlib.Path.

  • Fixed a leaked file handle when using --output-type none.

  • Removed shims to support versions of pikepdf that are no longer supported.


  • Declare support for pdfminer.six v20211012.


  • Fixed test suite failure when using pikepdf 3.2.0 that was compiled with pybind11 2.8.0. #843

  • Improve advice to user about using --max-image-mpixels if OCR fails for this reason.

  • Minor documentation fixes. (Thanks to @mara004.)

  • Don’t require importlib-metadata and importlib-resources backports on versions of Python where the standard library implementation is sufficient. (Thanks to Marco Genasci.)


  • Implemented --output-type=none to skip producing PDFs for applications that only want sidecar files (#787).

  • Fixed ambiguities in descriptions of behavior of --jbig2-lossy.

  • Various improvements to documentation.


  • Fixed build failure for the combination of PyPy 3.6 and pikepdf 3.0. This combination can work in a source build but does not work with wheels.

  • Accepted bot that wanted to upgrade our deprecated requirements.txt.

  • Documentation updates.

  • Replace pkg_resources and install dependency on setuptools with importlib-metadata and importlib-resources.

  • Fixed regression in hocrtransform causing text to be omitted when this renderer was used.

  • Fixed some typing errors.


  • When grafting text layers, use pikepdf’s unparse_content_stream if available.

  • Confirmed support for pluggy 1.0. (Thanks @QuLogic.)

  • Fixed some typing issues, improved pre-commit settings, and fixed issues flagged by linters.

  • PyPy 7.3.3 (=Python 3.6) is now supported. Note that PyPy does not necessarily run faster, because the vast majority of OCRmyPDF’s execution time is spent running OCR or generally executing native code. However, PyPy may bring speed improvements in some areas.


  • fixed interpretation of boolean env vars (#821).

  • Adjust CI scripts to test Tesseract 5 betas.

  • Document our support for the Tesseract 5 betas.


  • Indicate support for flask 2.x, watcher 2.x (#815, #816).


  • Fixed issue with selection of text when using the hOCR renderer (#813).

  • Fixed build errors with the Docker image by upgrading to a newer Ubuntu. Also set the timezone of this image to UTC.


  • Fixed a regression introduced in Pillow 8.3.0. Pillow no longer rounds DPI for image resolutions. We now account for this (#802).

  • We no longer use some API calls that are deprecated in the latest versions of pikepdf.

  • Improved error message when a language is requested that doesn’t look like a typical ISO 639-2 code.

  • Fixed some tests that attempted to symlink on Windows, breaking tests on a Windows desktop but not usually on CI.

  • Documentation fixes (thanks to @mara004)


  • Fixed invalid Tesseract version number on Windows (#795).

  • Documentation tweaks. Documentation build now depends on sphinx-issues package.


  • For security reasons we now require Pillow >= 8.2.x. (Older versions will continue to work if upgrading is not an option.)

  • The build system was reorganized to rely on setup.cfg instead of All changes should work with previously supported versions of setuptools.

  • The files in requirements/* are now considered deprecated but will be retained for v12. Instead use pip install ocrmypdf[test] instead of requirements/test.txt, etc. These files will be removed in v13.


  • Expand the list of languages supported by the hocr PDF renderer. Several languages were previously considered not supported, particularly those non-European languages that use the Latin alphabet.

  • Fixed a case where the exception stack trace was suppressed in verbose mode.

  • Improved documentation around commercial OCR.


  • Fixed exception thrown when using --remove-background on files containing small images (#769).

  • Improve documentation for description of adding language packs to the Docker image and corrected name of French language pack.


  • Fixed “invalid version number” for untagged tesseract versions (#770).


Breaking changes

  • Due to recent security issues in pikepdf, Pillow and reportlab, we now require newer versions of these libraries and some of their dependencies. (If necessary, package maintainers may override these versions at their discretion; lower versions will often work.)

  • We now use the “LeaveColorUnchanged” color conversion strategy when directing Ghostscript to create a PDF/A. Generally this is faster than performing a color conversion, which is not always necessary.

  • OCR text is now packaged in a Form XObject. This makes it easier to isolate OCR from other document content. However, some poorly implemented PDF text extraction algorithms may fail to detect the text.

  • Many API functions have stricter parameter checking or expect keyword arguments were they previously did not.

  • Some deprecated functions in ocrmypdf.optimize were removed.

  • The ocrmypdf.leptonica module is now deprecated, due to difficulties with the current strategy of ABI binding on newer platforms like Apple Silicon. It will be removed and replaced, either by repackaging Leptonica as an independent library using or using a different image processing library.

  • Continuous integration moved to GitHub Actions.

  • We no longer depend on pytest_helpers_namespace for testing.

New features

  • New plugin hook: get_progressbar_class, for progress reporting, allowing developers to replace the standard console progress bar with some other mechanism, such as updating a GUI progress bar.

  • New plugin hook: get_executor, for replacing the concurrency model. This is primarily to support execution on AWS Lambda, which does not support standard Python multiprocessing due to its lack of shared memory.

  • New plugin hook: get_logging_console, for replacing the standard way OCRmyPDF outputs its messages.

  • New plugin hook: filter_pdf_page, for modifying individual PDF pages produced by OCRmyPDF.

  • OCRmyPDF now runs on nonstandard execution environments that do not have interprocess semaphores, such as AWS Lambda and Android Termux. If the environment does not have semaphores, OCRmyPDF will automatically select an alternate process executor that does not use semaphores.

  • Continuous integration moved to GitHub Actions.

  • We now generate an ARM64-compatible Docker image alongside the x64 image. Thanks to @andkrause for doing most of the work in a pull request several months ago, which we were finally able to integrate now. Also thanks to @0x326 for review comments.


  • Fixed a possible deadlock on attempting to flush sys.stderr when older versions of Leptonica are in use.

  • Some worker processes inherited resources from their parents such as log handlers that may have also lead to deadlocks. These resources are now released.

  • Improvements to test coverage.

  • Removed vestiges of support for Tesseract versions older than 4.0.0-beta1 ( which ships with Ubuntu 18.04).

  • OCRmyPDF can now parse all of Tesseract version numbers, since several schemes have been in use.

  • Fixed an issue with parsing PDFs that contain images drawn at a scale of 0. (#761)

  • Removed a frequently repeated message about disabling mmap.


  • Exclude CCITT Group 3 images from being optimized. Some libraries OCRmyPDF uses do not seem to handle this obscure compression format properly. You may get errors or possible corrupted output images without this fix.


  • Updated pinned versions in main.txt, primarily to upgrade Pillow to 8.1.2, due to recently disclosed security vulnerabilities in that software.

  • The --sidecar parameter now causes an exception if set to the same file as the input or output PDF.


  • Some exceptions while attempting image optimization were only logged at the debug level, causing them to be suppressed. These errors are now logged appropriately.

  • Improved the error message related to --unpaper-args.

  • Updated documentation to mention the new conda distribution.


  • We now support using --sidecar in conjunction with --pages; these arguments used to be mutually exclusive. (#735)

  • Fixed a possible issue with PDF/A-1b generation. Acrobat complained that our PDFs use object streams. More robust PDF/A validators like veraPDF don’t consider this a problem, but we’ll honor Acrobat’s objection from here on. This may increase file size of PDF/A-1b files. PDF/A-2b files will not be affected.


  • Fixed a regression where the wrong page orientation would be produced when using arguments such as --deskew --rotate-pages (#730).


  • Fixed an issue with attempting optimize unusually narrow-width images by excluding these images from optimization (#732).

  • Remove an obsolete compatibility shim for a version of pikepdf that is no longer supported.


  • OCRmyPDF will now automatically register plugins from the same virtual environment with an appropriate setuptools entrypoint.

  • Refactor the plugin manager to remove unnecessary complications and make plugin registration more automatic.

  • PageContext and PdfContext are now formally part of the API, as they should have been, since they were part of ocrmypdf.pluginspec.


  • Fixed an issue where the output page size might differ by a fractional amount due to rounding, when --force-ocr was used and the page contained objects with multiple resolutions.

  • When determining the resolution at which to rasterize a page, we now consider printed text on the page as requiring a higher resolution. This fixes issues with certain pages being rendered with unacceptably low resolution text, but may increase output file sizes in some workflows where low resolution text is acceptable.

  • Added a workaround to fix an exception that occurs when trying to import ocrmypdf.leptonica on Apple ARM silicon (or potentially, other platforms that do not permit write+executable memory).


  • Fixed an issue where files may not be closed when the API is used.

  • Improved setup.cfg with better settings for test coverage.


  • Fixed AttributeError: 'NoneType' object has no attribute 'userunit' (#700), related to OCRmyPDF not properly forwarded an error message from pdfminer.six.

  • Adjusted typing of some arguments.

  • ocrmypdf.ocr now takes a threading.Lock for reasons outlined in the documentation.


  • Removed a redundant debug message.

  • Test suite now asserts that most patched functions are called when they should be.

  • Test suite now skips a test that fails on two particular versions of piekpdf.


  • Fixed support for Cygwin, hopefully.

  • Fixed an issue with the OCR_LOGLEVEL not being interpreted.


  • Fixed an issue where invalid pages ranges passed using the pages argument, such as “1-0” would cause unhandled exceptions.

  • Accepted a user-contributed to the Synology demo script in misc/

  • Clarified documentation about change of temporary file location

  • Fixed Python wheel tag which was incorrectly set to py35 even though we long since dropped support for Python 3.5.


  • When looking for Tesseract and Ghostscript, we now check the Windows Registry to see if their installers registered the location of their executables. This should help Windows users who have installed these programs to non-standard locations.

  • We now report on the progress of PDF/A conversion, since this operation is sometimes slow.

  • Improved command line completions.

  • The prefix of the temporary folder OCRmyPDF creates has been changed from com.github.ocrmypdf to Scripts that chose to depend on this prefix may need to be adjusted. (This has always been an implementation detail so is not considered part of the semantic versioning “contract”.)

  • Fixed #692, where a particular file with malformed fonts would flood an internal message cue by generating so many debug messages.

  • Fixed an exception on processing hOCR files with no page record. Tesseract is not known to generate such files.


  • Fixed an error message ‘called readLinearizationData for file that is not linearized’ that may occur when pikepdf 2.1.0 is used. (Upgrading to pikepdf 2.1.1 also fixes the issue.)

  • File watcher now automatically includes .PDF in addition to .pdf to better support case sensitive file systems.

  • Some documentation and comment improvements.


  • If unpaper outputs non-UTF-8 data, quietly fix this rather than choke on the conversion. (Possibly addresses #671.)


  • Explicitly require pikepdf 2.0.0 or newer when running on Python 3.9. (There are concerns about the stability of pybind11 2.5.x with Python 3.9, which is used in pikepdf 1.x.)

  • Fixed another issue related to page rotation.

  • Fixed an issue where image marked as image masks were not properly considered as optimization candidates.

  • On some systems, unpaper seems to be unable to process the PNGs we offer it as input. We now convert the input to PNM format, which unpaper always accepts. Fixes #665 and #667.

  • DPI sent to unpaper is now rounded to a more reasonable number of decimal digits.

  • Debug and error messages from unpaper were being suppressed.

  • Some documentation tweaks.


  • Declare support for new versions: pdfminer.six 20201018 and pikepdf 2.x

  • Fixed warning related to --pdfa-image-compression that appears at the wrong time.


  • The “OCR” step is describing as “Image processing” in the output messages when OCR is disabled, to better explain the application’s behavior.

  • Debug logs are now only created when run as a command line, and not when OCR is performed for an API call. It is the calling application’s responsibility to set up logging.

  • For PDFs with a low number of pages, we gathered information about the input PDF in a thread rather than process (when there are more pages). When run as a thread, we did not close the file handle to the working PDF, leaking one file handle per call of ocrmypdf.ocr.

  • Fixed an issue where debug messages send by child worker processes did not match the log settings of parent process, causing messages to be dropped. This affected macOS and Windows only where the parent process is not forked.

  • Fixed the hookspec of rasterize_pdf_page to remove default parameters that were not handled in an expected way by pluggy.

  • Fixed another issue with automatic page rotation (#658) due to the issue above.


  • Fixed an issue where optimization of a 1-bit image with a color palette or associated ICC that was optimized to JBIG2 could have its colors inverted.


  • Fixed an issue with optimizing PNG-type images that had soft masks or image masks. This is a regression introduced in (or about) v11.1.0.

  • Improved type checking of the plugins parameter for the ocrmypdf.ocr API call.


  • Fixed hOCR renderer writing the text in roughly reverse order. This should not affect reasonably smart PDF readers that properly locate the position of all text, but may confuse those that rely on the order of objects in the content stream. (#642)


  • We now avoid using named temporary files when using pngquant allowing containerized pngquant installs to be used.

  • Clarified an error message.

  • Highest number of 1’s in a release ever!


  • Fixed page rotation issues: #634, #589.

  • Fixed some cases where optimization created an invalid image such as a 1-bit “RGB” image: #629, #620.

  • Page numbers are now displayed in debug logs when pages are being grafted.

  • ocrmypdf.optimize.rewrite_png and ocrmypdf.optimize.rewrite_png_as_g4 were marked deprecated. Strictly speaking these should have been internal APIs, but they were never hidden.

  • As a precaution, pikepdf mmap-based file access has been disabled due to a rare race condition that causes a crash when certain objects are deallocated. The problem is likely in pikepdf’s dependency pybind11.

  • Extended the example plugin to demonstrate conversion to mono.


  • Fixed #612, TypeError exception. Fixed by eliminating unnecessary repair of input PDF metadata in memory.


  • Blacklist pdfminer.six 20200720, which has a regression fixed in 20200726.

  • Approve img2pdf 0.4 as it passes tests.

  • Clarify that the GPL-3 portion of was removed with the changes in v11.0.0; the debian/copyright file did not properly annotate this change.


  • Project license changed to Mozilla Public License 2.0. Some miscellaneous code is now under MIT license and non-code content/media remains under CC-BY-SA 4.0. License changed with approval of all people who were found to have contributed to GPLv3 licensed sections of the project. (#600)

  • Because the license changed, this is being treated as a major version number change; however, there are no known breaking changes in functional behavior or API compared to v10.x.


  • Fixed a “KeyError: ‘dpi’” error message when using --threshold on an image. (#607)


  • Fixed a case where we reported “no reason” for a file size increase, when we could determine the reason.

  • Enabled support for pdfminer.six 20200726.


  • Fixed a number of test suite failures with pdfminer.six older than version 20200402.

  • Enabled support for pdfminer.six 20200720.


  • Fixed an issue where we would consider images that were already JBIG2-encoded for optimization, potentially producing a less optimized image than the original. We do not believe this issue would ever cause an image to loss fidelity.

  • Where available, pikepdf memory mapping is now used. This improves performance.

  • When Leptonica 1.79+ is installed, use its new error handling API to avoid a “messy” redirection of stderr which was necessary to capture its error messages.

  • For older versions of Leptonica, added a new thread level lock. This fixes a possible race condition in handling error conditions in Leptonica (although there is no evidence it ever caused issues in practice).

  • Documentation improvements and more type hinting.


  • Disabled calculation of text box order with pdfminer. We never needed this result and it is expensive to calculate on files with complex pre-existing text.

  • Fixed plugin manager to accept Path(plugin) as a path to a plugin.

  • Fixed some typing errors.

  • Documentation improvements.


  • Update Docker image to use Ubuntu 20.04.

  • Fixed issue PDF/A acquires title “Untitled” after conversion. (#582)

  • Fixed a problem where, when using --pdf-renderer hocr, some text would be missing from the output when using a more recent version of Tesseract. Tesseract began adding more detailed markup about the semantics of text that our HOCR transform did not recognize, so it ignored them. This option is not the default. If necessary --redo-ocr also redoing OCR to fix such issues.

  • Fixed an error in Python 3.9 beta, due to removal of deprecated Element.getchildren(). (#584)

  • Implemented support using the API with BytesIO and other file stream objects. (#545)


  • Fixed OMP_THREAD_LIMIT set to invalid value error messages on some input files. (The error was harmless, apart from less than optimal performance in some cases.)


  • Previously, we --clean-final would cause an unpaper-cleaned page image to be produced twice, which was necessary in some cases but not in general. We now take this optimization opportunity and reuse the image if possible.

  • We now provide PNG files as input to unpaper, since it accepts them, instead of generating PPM files which can be very large. This can improve performance and temporary disk usage.

  • Documentation updated for plugins.


  • Fixed regression when -l lang1+lang2 is used from command line.


Breaking changes

  • Support for pdfminer.six version 20181108 has been dropped, along with a monkeypatch that made this version work.

  • Output messages are now displayed in color (when supported by the terminal) and prefixes describing the severity of the message are removed. As such programs that parse OCRmyPDF’s log message will need to be revised. (Please consider using OCRmyPDF as a library instead.)

  • The minimum version for certain dependencies has increased.

  • Many API changes; see developer changes.

  • The Python libraries pluggy and coloredlogs are now required.

New features and improvements

  • PDF page scanning is now parallelized across CPUs, speeding up this phase dramatically for files with a high page counts.

  • PDF page scanning is optimized, addressing some performance regressions.

  • PDF page scanning is no longer run on pages that are not selected when the --pages argument is used.

  • PDF page scanning is now independent of Ghostscript, ending our past reliance on this occasionally unstable feature in Ghostscript.

  • A plugin architecture has been added, currently allowing one to more easily use a different OCR engine or PDF renderer from Tesseract and Ghostscript, respectively. A plugin can also override some decisions, such changing the OCR settings after initial scanning.

  • Colored log messages.

Developer changes

  • The test spoofing mechanism, used to test correct handling of failures in Tesseract and Ghostscript, has been removed in favor of using plugins for testing. The spoofing mechanism was fairly complex and required many special hacks for Windows.

  • Code describing the resolution in DPI of images was refactored into a ocrmypdf.helpers.Resolution class.

  • The module ocrmypdf._exec is now private to OCRmyPDF.

  • The ocrmypdf.hocrtransform module has been updated to follow PEP8 naming conventions.

  • Ghostscript is no longer used for finding the location of text in PDFs, and APIs related to this feature have been removed.

  • Lots of internal reorganization to support plugins.


  • Fixed an issue where OCRmyPDF would ignore text inside Form XObject when making certain decisions about whether a document already had text.

  • Fixed file size increase warning to take overhead of small files into account.

  • Added instructions for installing on Cygwin.


  • Fixed an issue where unexpected files in the %PROGRAMFILES%\gs directory (Windows) caused an exception.

  • Mark pdfminer.six 20200517 as supported.

  • If jbig2enc is missing and optimization is requested, a warning is issued instead of an error, which was the intended behavior.

  • Documentation updates.


  • Fixed issue where only the first PNG (FlateDecode) image in a file would be considered for optimization. File sizes should be improved from here on.

  • Fixed a startup crash when the chosen language was Japanese (#543).

  • Added options to configure polling and log level to


  • Fixed an issue with ocrmypdf.ocr(...language=) not accepting a list of languages as documented.

  • Updated to confirm that pdfminer.six version 20200402 is supported.


  • Fixed version check failing when used with qpdf 10.0.0.

  • Added some missing type annotations.

  • Updated documentation to warn about need for “ifmain” guard and Windows.


  • Fixed an error in if OCR_JSON_SETTINGS was not defined.

  • Ghostscript 9.51 is now blacklisted, due to numerous problems with this version.

  • Added a workaround for a problem with “txtwrite” in Ghostscript 9.52.

  • Fixed an issue where the incorrect number of threads used was shown when OMP_THREAD_LIMIT was manipulated.

  • Removed a possible performance bottlenecks for files that use hundreds to thousands of images on the same page.

  • Documentation improvements.

  • Optimization will now be applied to some monochrome images that have a color profile defined instead of only black and white.

  • ICC profiles are consulted when determining the simplified colorspace of an image.


  • Documentation improvements - thanks to many users for their contributions!

    • Fixed installation instructions for ArchLinux (@pigmonkey)

    • Updated installation instructions for FreeBSD and other OSes (@knobix)

    • Added instructions for using Docker Compose with watchdog (@ianalexander, @deisi)

    • Other miscellany (@mb720, @toy, @caiofacchinato)

    • Some scripts provided in the documentation have been migrated out so that they can be copied out as whole files, and to ensure syntax checking is maintained.

  • Fixed an error that caused bash completions to fail on macOS. (#502, #504; @AlexanderWillner)

  • Fixed a rare case where OCRmyPDF threw an exception while processing a PDF with the wrong object type in its /Trailer /Info. The error is now logged and incorrect object is ignored. (#497)

  • Removed potentially non-free file enron1.pdf and simplified the test that used it.

  • Removed potentially non-free file misc/media/logo.afdesign.


  • Fixed a regression with transferring metadata from the input PDF to the output PDF in certain situations.

  • pdfminer.six is now supported up to version 2020-01-24.

  • Messages are explaining page rotation decisions are now shown at the standard verbosity level again when --rotate-pages. In some previous version they were set to debug level messages that only appeared with the parameter -v1.

  • Improvements to misc/ Thanks to @ianalexander and @svenihoney.

  • Documentation improvements.


  • Added API functions to measure OCR quality.

  • Modest improvements to handling PDFs with difficult/non compliant metadata.


  • Updated recommended dependency versions.

  • Improvements to test coverage and changes to facilitate better measurement of test coverage, such as when tests run in subprocesses.

  • Improvements to error messages when Leptonica is not installed correctly.

  • Fixed use of pytest “session scope” that may have caused some intermittent CI failures.

  • When the argument --keep-temporary-files or verbosity is set to -v1, a debug log file is generated in the working temporary folder.


  • Improved native Windows support: we now check in the obvious places in the “Program Files” folders installations of Tesseract and Ghostscript, rather than relying on the user to edit PATH to specify their location. The PATH environment variable can still be used to differentiate when multiple installations are present or the programs are installed to non- standard locations.

  • Fixed an exception on parsing Ghostscript error messages.

  • Added an improved example demonstrating how to set up a watched folder for automated OCR processing (thanks to @ianalexander for the contribution).


  • Native Windows is now supported.

  • Continuous integration moved to Azure Pipelines.

  • Improved test coverage and speed of tests.

  • Fixed an issue where a page that was originally a JPEG would be saved as a PNG, increasing file size. This occurred only when a preprocessing option was selected along with --output-type=pdf and all images on the original page were JPEGs. Regression since v7.0.0.

  • OCRmyPDF no longer depends on the QPDF executable qpdf or libqpdf. It uses pikepdf (which in turn depends on libqpdf). Package maintainers should adjust dependencies so that OCRmyPDF no longer calls for libqpdf on its own. For users of Python binary wheels, this change means a separate installation of QPDF is no longer necessary. This change is mainly to simplify installation on Windows.

  • Fixed a rare case where log messages from Tesseract would be discarded.

  • Fixed incorrect function signature for pixFindPageForeground, causing exceptions on certain platforms/Leptonica versions.


  • Expand the range of pdfminer.six versions that are supported.

  • Fixed Docker build when using pikepdf 1.7.0.

  • Fixed documentation to recommend using pip from


  • Improved diagnostics when file size increases at output. Now warns if JBIG2 or pngquant were not available.

  • pikepdf 1.7.0 is now required, to pick up changes that remove the need for a source install on Linux systems running Python 3.8.


  • The Alpine Docker image (jbarlow83/ocrmypdf-alpine) has been dropped due to the difficulties of supporting Alpine Linux.

  • The primary Docker image (jbarlow83/ocrmypdf) has been improved to take on the extra features that used to be exclusive to the Alpine image.

  • No changes to application code.

  • pdfminer.six version 20191020 is now supported.


  • Fixed compatibility with Python 3.8 (but requires source install for the moment).

  • Fixed Tesseract settings for --user-words and --user-patterns.

  • Changed to pikepdf 1.6.5 (for Python 3.8).

  • Changed to Pillow 6.2.0 (to mitigate a security vulnerability in earlier Pillow).

  • A debug message now mentions when English is automatically selected if the locale is not English.


  • Embed an encoded version of the sRGB ICC profile in the intermediate Postscript file (used for PDF/A conversion). Previously we included the filename, which required Postscript to run with file access enabled. For security, Ghostscript 9.28 enables -dSAFER and as such, no longer permits access to any file by default. This fix is necessary for compatibility with Ghostscript 9.28.

  • Exclude a test that sometimes times out and fails in continuous integration from the standard test suite.


  • The image optimizer now skips optimizing flate (PNG) encoded images in some situations where the optimization effort was likely wasted.

  • The image optimizer now ignores images that specify arbitrary decode arrays, since these are rare.

  • Fixed an issue that caused inversion of black and white in monochrome images. We are not certain but the problem seems to be linked to Leptonica 1.76.0 and older.

  • Fixed some cases where the test suite failed if English or German Tesseract language packs were not installed.

  • Fixed a runtime error if the Tesseract English language is not installed.

  • Improved explicit closing of Pillow images after use.

  • Actually fixed of Alpine Docker image build.

  • Changed to pikepdf 1.6.3.


  • Fixed test suite failing when either of optional dependencies unpaper and pngquant were missing.

  • Attempted fix of Alpine Docker image build.

  • Documented that FreeBSD ports are now available.

  • Changed to pikepdf 1.6.1.


Breaking changes

  • The --mask-barcodes experimental feature has been dropped due to poor reliability and occasional crashes, both due to the underlying library that implements this feature (Leptonica).

  • The -v (verbosity level) parameter now accepts only 0, 1, and 2.

  • Dropped support for Tesseract 4.00.00-alpha releases. Tesseract 4.0 beta and later remain supported.

  • Dropped the ocrmypdf-polyglot and ocrmypdf-webservice images.

New features

  • Added a high level API for applications that want to integrate OCRmyPDF. Special thanks to Martin Wind (@mawi1988) whose made significant contributions to this effort.

  • Added progress bars for long-running steps. ■■■■■■■□□

  • We now create linearized (“fast web view”) PDFs by default. The new parameter --fast-web-view provides control over when this feature is applied.

  • Added a new --pages feature to limit OCR to only a specific page range. The list may contain commas or single pages, such as 1, 3, 5-11.

  • When the number of pages is small compared to the number of allowed jobs, we run Tesseract in multithreaded (OpenMP) mode when available. This should improve performance on files with low page counts.

  • Removed dependency on ruffus, and with that, the non-reentrancy restrictions that previous made an API impossible.

  • Output and logging messages overhauled so that ocrmypdf may be integrated into applications that use the logging module.

  • pikepdf 1.6.0 is required.

  • Added a logo. 😊

Bug fixes

  • Pages with vector artwork are treated as full color. Previously, vectors were ignored when considering the colorspace needed to cover a page, which could cause loss of color under certain settings.

  • Test suite now spawns processes less frequently, allowing more accurate measurement of code coverage.

  • Improved test coverage.

  • Fixed a rare division by zero (if optimization produced an invalid file).

  • Updated Docker images to use newer versions.

  • Fixed images encoded as JBIG2 with a colorspace other than /DeviceGray were not interpreted correctly.

  • Fixed a OCR text-image registration (i.e. alignment) problem when the page when MediaBox had a nonzero corner.


  • Dropped workaround for macOS that allowed it work without pdfminer.six, now a proper sdist release of pdfminer.six is available.

  • pikepdf 1.5.0 is now required.


  • Fixed an issue where PDFs with malformed metadata would be rendered as blank pages. #398.


  • Improved the strategy for updating pages when a new image of the page was produced. We now attempt to preserve more content from the original file, for annotations in particular.

  • For PDFs with more than 100 pages and a sequence where one PDF page was replaced and one or more subsequent ones were skipped, an intermediate file would be corrupted while grafting OCR text, causing processing to fail. This is a regression, likely introduced in v8.2.4.

  • Previously, we resized the images produced by Ghostscript by a small number of pixels to ensure the output image size was an exactly what we wanted. Having discovered a way to get Ghostscript to produce the exact image sizes we require, we eliminated the resizing step.

  • Command line completions for bash are now available, in addition to fish, both in misc/completion. Package maintainers, please install these so users can take advantage.

  • Updated requirements.

  • pikepdf 1.3.0 is now required.


  • Fixed a false positive while checking for a certain type of PDF that only Acrobat can read. We now more accurately detect Acrobat-only PDFs.

  • OCRmyPDF holds fewer open file handles and is more prompt about releasing those it no longer needs.

  • Minor optimization: we no longer traverse the table of contents to ensure all references in it are resolved, as changes to libqpdf have made this unnecessary.

  • pikepdf 1.2.0 is now required.


  • Fixed that --mask-barcodes would occasionally leave a unwanted temporary file named junkpixt in the current working folder.

  • Fixed (hopefully) handling of Leptonica errors in an environment where a non-standard sys.stderr is present.

  • Improved help text for --verbose.


  • Fixed a regression from v8.2.0, an exception that occurred while attempting to report that unpaper or another optional dependency was unavailable.

  • In some cases, ocrmypdf [-c|--clean] failed to exit with an error when unpaper is not installed.


  • This release was canceled.


  • A major improvement to our Docker image is now available thanks to hard work contributed by @mawi12345. The new Docker image, ocrmypdf-alpine, is based on Alpine Linux, and includes most of the functionality of three existed images in a smaller package. This image will replace the main Docker image eventually but for now all are being built. See documentation for details.

  • Documentation reorganized especially around the use of Docker images.

  • Fixed a problem with PDF image optimization, where the optimizer would unnecessarily decompress and recompress PNG images, in some cases losing the benefits of the quantization it just had just performed. The optimizer is now capable of embedding PNG images into PDFs without transcoding them.

  • Fixed a minor regression with lossy JBIG2 image optimization. All JBIG2 candidates images were incorrectly placed into a single optimization group for the whole file, instead of grouping pages together. This usually makes a larger JBIG2Globals dictionary and results in inferior compression, so it worked less well than designed. However, quality would not be impacted. Lossless JBIG2 was entirely unaffected.

  • Updated dependencies, including pikepdf to 1.1.0. This fixes #358.

  • The install-time version checks for certain external programs have been removed from These tests are now performed at run-time.

  • The non-standard option to override install-time checks ( install --force) is now deprecated and prints a warning. It will be removed in a future release.


  • 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

  • OCRmyPDF now always calls os.nice(5) to signal to operating systems that it is a background process.


  • Fixed an exception when parsing PDFs that are missing a required field. #325

  • pikepdf 1.0.5 is now required, to address some other PDF parsing issues.


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

  • 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.


  • --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)

  • 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)


  • 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


  • 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 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 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.


  • Fixed 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.


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 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)

  • 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.


  • 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)

  • pikepdf 0.3.3 is now required.

  • Fixed #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)

  • is now served in GitHub markdown instead of reStructuredText.


  • Blacklist Ghostscript 9.24, now that 9.25 is available and fixes many regressions in 9.24.


  • 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.


  • Fixed 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.


  • Fixed #284, an error when parsing inline images that have are also image masks, by upgrading pikepdf to 0.3.1


  • Fixed a regression with --rotate-pages on pages that already had rotations applied. (#279)

  • Improve quality of page rotation in some cases by rasterizing a higher quality preview image. (#281)


  • Fixed compatibility with img2pdf >= 0.3.0 by rejecting input images that have an alpha channel

  • Add forward compatibility for pikepdf 0.3.0 (unrelated to img2pdf)

  • Various documentation updates for v7.0.0 changes


  • The core algorithm for combining OCR layers with existing PDF pages has been rewritten and improved considerably. PDFs are no longer split into single page PDFs for processing; instead, images are rendered and the OCR results are grafted onto the input PDF. The new algorithm uses less temporary disk space and is much more performant especially for large files.

  • New dependency: pikepdf. pikepdf is a powerful new Python PDF library driving the latest OCRmyPDF features, built on the QPDF C++ library (libqpdf).

  • New feature: PDF optimization with -O or --optimize. After OCR, OCRmyPDF will perform image optimizations relevant to OCR PDFs.

    • If a JBIG2 encoder is available, then monochrome images will be converted, with the potential for huge savings on large black and white images, since JBIG2 is far more efficient than any other monochrome (bi-level) compression. (All known US patents related to JBIG2 have probably expired, but it remains the responsibility of the user to supply a JBIG2 encoder such as jbig2enc. OCRmyPDF does not implement JBIG2 encoding.)

    • If pngquant is installed, OCRmyPDF will optionally use it to perform lossy quantization and compression of PNG images.

    • The quality of JPEGs can also be lowered, on the assumption that a lower quality image may be suitable for storage after OCR.

    • This image optimization component will eventually be offered as an independent command line utility.

    • Optimization ranges from -O0 through -O3, where 0 disables optimization and 3 implements all options. 1, the default, performs only safe and lossless optimizations. (This is similar to GCC’s optimization parameter.) The exact type of optimizations performed will vary over time.

  • Small amounts of text in the margins of a page, such as watermarks, page numbers, or digital stamps, will no longer prevent the rest of a page from being OCRed when --skip-text is issued. This behavior is based on a heuristic.

  • Removed features

    • The deprecated --pdf-renderer tesseract PDF renderer was removed.

    • -g, the option to generate debug text pages, was removed because it was a maintenance burden and only worked in isolated cases. HOCR pages can still be previewed by running the with appropriate settings.

  • Removed dependencies

    • PyPDF2

    • defusedxml

    • PyMuPDF

  • The sandwich PDF renderer can be used with all supported versions of Tesseract, including that those prior to v3.05 which don’t support -c textonly. (Tesseract v4.0.0 is recommended and more efficient.)

  • --pdf-renderer auto option and the diagnostics used to select a PDF renderer now work better with old versions, but may make different decisions than past versions.

  • If everything succeeds but PDF/A conversion fails, a distinct return code is now returned (ExitCode.pdfa_conversion_failed (10)) where this situation previously returned ExitCode.invalid_output_pdf (4). The latter is now returned only if there is some indication that the output file is invalid.

  • Notes for downstream packagers

    • There is also a new dependency on python-xmp-toolkit which in turn depends on libexempi3.

    • It may be necessary to separately pip install pycparser to avoid another Python 3.7 issue.


  • 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.


  • 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


  • Fixed compatibility with img2pdf >= 0.3.0 by rejecting input images that have an alpha channel

  • This version will be included in Ubuntu 18.10


  • Backport compatibility fixes for Python 3.7 and ruffus 2.7.0 from v7.0.0

  • Backport fix to ignore masks when deciding what colors are on a page

  • Backport some minor improvements from v7.0.0: better argument validation and warnings about the Tesseract 4.0.0 --user-words regression


  • Fixed recent versions of Tesseract (after 4.0.0-beta1) not being detected as supporting the sandwich renderer (#271).


  • Docker: The Docker image ocrmypdf-tess4 has been removed. The main Docker images, ocrmypdf and ocrmypdf-polyglot now use Ubuntu 18.04 as a base image, and as such Tesseract 4.0.0-beta1 is now the Tesseract version they use. There is no Docker image based on Tesseract 3.05 anymore.

  • Creation of PDF/A-3 is now supported. However, there is no ability to attach files to PDF/A-3.

  • Lists more reasons why the file size might grow.

  • Fixed #262, --remove-background error on PDFs contained colormapped (paletted) images.

  • Fixed another XMP metadata validation issue, in cases where the input file’s creation date has no timezone and the creation date is not overridden.


  • Fixed #253, a possible division by zero when using the hocr renderer.

  • Fixed incorrectly formatted <xmp:ModifyDate> field inside XMP metadata for PDF/As. veraPDF flags this as a PDF/A validation failure. The error is caused the timezone and final digit of the seconds of modified time to be omitted, so at worst the modification time stamp is rounded to the nearest 10 seconds.


  • Fixed #248 --clean argument may remove OCR from left column of text on certain documents. We now set --layout none to suppress this.

  • The test cache was updated to reflect the change above.

  • Change test suite to accommodate Ghostscript 9.23’s new ability to insert JPEGs into PDFs without transcoding.

  • XMP metadata in PDFs is now examined using defusedxml for safety.

  • If an external process exits with a signal when asked to report its version, we now print the system error message instead of suppressing it. This occurred when the required executable was found but was missing a shared library.

  • qpdf 7.0.0 or newer is now required as the test suite can no longer pass without it.


  • An apparent regression in Ghostscript 9.23 will cause some ocrmypdf output files to become invalid in rare cases; the workaround for the moment is to set --force-ocr.


  • Fixed #247, /CreationDate metadata not copied from input to output.

  • A warning is now issued when Python 3.5 is used on files with a large page count, as this case is known to regress to single core performance. The cause of this problem is unknown.


  • Upgrade to PyMuPDF v1.12.5 which includes a more complete fix to #239.

  • Add defusedxml dependency.


  • Fixed text being reported as found on all pages if PyMuPDF is not installed.


  • PyMuPDF is now an optional but recommended dependency, to alleviate installation difficulties on platforms that have less access to PyMuPDF than the author anticipated. (For version 6.x only) install OCRmyPDF with pip install ocrmypdf[fitz] to use it to its full potential.

  • Fixed FileExistsError that could occur if OCR timed out while it was generating the output file. (#218)

  • Fixed table of contents/bookmarks all being redirected to page 1 when generating a PDF/A (with PyMuPDF). (Without PyMuPDF the table of contents is removed in PDF/A mode.)

  • Fixed “RuntimeError: invalid key in dict” when table of contents/bookmarks titles contained the character ). (#239)

  • Added a new argument --skip-repair to skip the initial PDF repair step if the PDF is already well-formed (because another program repaired it).


  • The software license has been changed to GPLv3 [it has since changed again]. Test resource files and some individual sources may have other licenses.

  • OCRmyPDF now depends on PyMuPDF. Including PyMuPDF is the primary reason for the change to GPLv3.

  • Other backward incompatible changes

    • The OCRMYPDF_TESSERACT, OCRMYPDF_QPDF, OCRMYPDF_GS and OCRMYPDF_UNPAPER environment variables are no longer used. Change PATH if you need to override the external programs OCRmyPDF uses.

    • The ocrmypdf package has been moved to src/ocrmypdf to avoid issues with accidental import.

    • The function ocrmypdf.exec.get_program was removed.

    • The deprecated module ocrmypdf.pageinfo was removed.

    • The --pdf-renderer tess4 alias for sandwich was removed.

  • Fixed an issue where OCRmyPDF failed to detect existing text on pages, depending on how the text and fonts were encoded within the PDF. (#233, #232)

  • Fixed an issue that caused dramatic inflation of file sizes when --skip-text --output-type pdf was used. OCRmyPDF now removes duplicate resources such as fonts, images and other objects that it generates. (#237)

  • Improved performance of the initial page splitting step. Originally this step was not believed to be expensive and ran in a process. Large file testing revealed it to be a bottleneck, so it is now parallelized. On a 700 page file with quad core machine, this change saves about 2 minutes. (#234)

  • The test suite now includes a cache that can be used to speed up test runs across platforms. This also does not require computing checksums, so it’s faster. (#217)


  • Fixed an issue that caused poor CPU utilization on machines with more than 4 cores when running Tesseract 4. (Related to #217.)

  • The ‘hocr’ renderer has been improved. The ‘sandwich’ and ‘tesseract’ renderers are still better for most use cases, but ‘hocr’ may be useful for people who work with the PDF.js renderer in English/ASCII languages. (#225)

    • It now formats text in a matter that is easier for certain PDF viewers to select and extract copy and paste text. This should help macOS Preview and PDF.js in particular.

    • The appearance of selected text and behavior of selecting text is improved.

    • The PDF content stream now uses relative moves, making it more compact and easier for viewers to determine when two words on the same line.

    • It can now deal with text on a skewed baseline.

    • Thanks to @cforcey for the pull request, @jbreiden for many helpful suggestions, @ctbarbour for another round of improvements, and @acaloiaro for an independent review.


  • Suppress two debug messages that were too verbose


  • Development branch accidentally tagged as release. Do not use.


  • Fixed #219: change how the final output file is created to avoid triggering permission errors when the output is a special file such as /dev/null

  • Fixed test suite failures due to a qpdf 8.0.0 regression and Python 3.5’s handling of symlink

  • The “encrypted PDF” error message was different depending on the type of PDF encryption. Now a single clear message appears for all types of PDF encryption.

  • ocrmypdf is now in Homebrew. Homebrew users are advised to the version of ocrmypdf in the official homebrew-core formulas rather than the private tap.

  • Some linting


  • Fixed #216: preserve “text as curves” PDFs without rasterizing file

  • Related to the above, messages about rasterizing are more consistent

  • For consistency versions minor releases will now get the trailing .0 they always should have had.


  • Add new argument --max-image-mpixels. Pillow 5.0 now raises an exception when images may be decompression bombs. This argument can be used to override the limit Pillow sets.

  • Fixed output page cropped when using the sandwich renderer and OCR is skipped on a rotated and image-processed page

  • A warning is now issued when old versions of Ghostscript are used in cases known to cause issues with non-Latin characters

  • Fixed a few parameter validation checks for -output-type pdfa-1 and pdfa-2


  • Fixed #181: fix final merge failure for PDFs with more pages than the system file handle limit (ulimit -n)

  • Fixed #200: an uncommon syntax for formatting decimal numbers in a PDF would cause qpdf to issue a warning, which ocrmypdf treated as an error. Now this the warning is relayed.

  • Fixed an issue where intermediate PDFs would be created at version 1.3 instead of the version of the original file. It’s possible but unlikely this had side effects.

  • A warning is now issued when older versions of qpdf are used since issues like #200 cause qpdf to infinite-loop

  • Address issue #140: if Tesseract outputs invalid UTF-8, escape it and print its message instead of aborting with a Unicode error

  • Adding previously unlisted setup requirement, pytest-runner

  • Update documentation: fix an error in the example script for Synology with Docker images, improved security guidance, advised pip install --user


  • If a subprocess fails to report its version when queried, exit cleanly with an error instead of throwing an exception

  • Added test to confirm that the system locale is Unicode-aware and fail early if it’s not

  • Clarified some copyright information

  • Updated pinned requirements.txt so the homebrew formula captures more recent versions


  • Fixed a regression from v5.4.1 that caused sidecar files to be created as empty files


  • Add workaround for Tesseract v4.00alpha crash when trying to obtain orientation and the latest language packs are installed


  • Change wording of a deprecation warning to improve clarity

  • Added option to generate PDF/A-1b output if desired (--output-type pdfa-1); default remains PDF/A-2b generation

  • Update documentation


  • Fixed missing error message that should occur when trying to force --pdf-renderer sandwich on old versions of Tesseract

  • Update copyright information in test files

  • Set system LANG to UTF-8 in Dockerfiles to avoid UTF-8 encoding errors


  • Fixed a broken test case related to language packs


  • Fixed wrong return code given for missing Tesseract language packs

  • Fixed “brew audit” crashing on Travis when trying to auto-brew


  • Added --user-words and --user-patterns arguments which are forwarded to Tesseract OCR as words and regular expressions respective to use to guide OCR. Supplying a list of subject-domain words should assist Tesseract with resolving words. (#165)

  • Using a non Latin-1 language with the “hocr” renderer now warns about possible OCR quality and recommends workarounds (#176)

  • Output file path added to error message when that location is not writable (#175)

  • Otherwise valid PDFs with leading whitespace at the beginning of the file are now accepted


  • When using Tesseract 3.05.01 or newer, OCRmyPDF will select the “sandwich” PDF renderer by default, unless another PDF renderer is specified with the --pdf-renderer argument. The previous behavior was to select --pdf-renderer=hocr.

  • The “tesseract” PDF renderer is now deprecated, since it can cause problems with Ghostscript on Tesseract 3.05.00

  • The “tess4” PDF renderer has been renamed to “sandwich”. “tess4” is now a deprecated alias for “sandwich”.


  • Files with pages larger than 200” (5080 mm) in either dimension are now supported with --output-type=pdf with the page size preserved (in the PDF specification this feature is called UserUnit scaling). Due to Ghostscript limitations this is not available in conjunction with PDF/A output.


  • Fixed #169, exception due to failure to create sidecar text files on some versions of Tesseract 3.04, including the jbarlow83/ocrmypdf Docker image


  • Backward incompatible changes

    • Support for Python 3.4 dropped. Python 3.5 is now required.

    • Support for Tesseract 3.02 and 3.03 dropped. Tesseract 3.04 or newer is required. Tesseract 4.00 (alpha) is supported.

    • The script was removed.

  • Add a new feature, --sidecar, which allows creating “sidecar” text files which contain the OCR results in plain text. These OCR text is more reliable than extracting text from PDFs. Closes #126.

  • New feature: --pdfa-image-compression, which allows overriding Ghostscript’s lossy-or-lossless image encoding heuristic and making all images JPEG encoded or lossless encoded as desired. Fixes #163.

  • Fixed #143, added --quiet to suppress “INFO” messages

  • Fixed #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)


  • Fixed #156, ‘NoneType’ object has no attribute ‘getObject’ on pages with no optional /Contents record. This should resolve all issues related to pages with no /Contents record.

  • Fixed #158, ocrmypdf now stops and terminates if Ghostscript fails on an intermediate step, as it is not possible to proceed.

  • Fixed #160, exception thrown on certain invalid arguments instead of error message


  • Automated update of macOS homebrew tap

  • Fixed #154, KeyError ‘/Contents’ when searching for text on blank pages that have no /Contents record. Note: incomplete fix for this issue.


  • Fixed --skip-big raising an exception if a page contains no images (#152) (thanks to @TomRaz)

  • Fixed an issue where pages with no images might trigger “cannot write mode P as JPEG” (#151)


  • Added a workaround for Ghostscript 9.21 and probably earlier versions would fail with the error message “VMerror -25”, due to a Ghostscript bug in XMP metadata handling

  • High Unicode characters (U+10000 and up) are no longer accepted for setting metadata on the command line, as Ghostscript may not handle them correctly.

  • 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


  • Fixed #147, --pdf-renderer tess4 --clean will produce an oversized page containing the original image in the bottom left corner, due to loss DPI information.

  • Make “using Tesseract 4.0” warning less ominous

  • Set up machinery for homebrew OCRmyPDF tap


  • Fixed #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


  • PDFs containing “Form XObjects” are now supported (issue #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


  • The Docker images (ocrmypdf, ocrmypdf-polyglot, ocrmypdf-tess4) are now based on Ubuntu 16.10 instead of Debian stretch

    • This makes supporting the Tesseract 4 image easier

    • This could be a disruptive change for any Docker users who built customized these images with their own changes, and made those changes in a way that depends on Debian and not Ubuntu

  • 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


  • To prevent a TIFF output error caused by img2pdf >= 0.2.1 and Pillow <= 3.4.2, dependencies have been tightened

  • The Tesseract 4.00 simultaneous process limit was increased from 1 to 2, since it was observed that 1 lowers performance

  • Documentation improvements to describe the --tesseract-config feature

  • Added test cases and fixed error handling for --tesseract-config

  • Tweaks to to deal with issues in the v4.4 release


  • Tesseract 4.00 is now supported on an experimental basis.

    • A new rendering option --pdf-renderer tess4 exploits Tesseract 4’s new text-only output PDF mode. See the documentation on PDF Renderers for details.

    • The --tesseract-oem argument allows control over the Tesseract 4 OCR engine mode (tesseract’s --oem). Use --tesseract-oem 2 to enforce the new LSTM mode.

    • Fixed poor performance with Tesseract 4.00 on Linux

  • Fixed an issue that caused corruption of output to stdout in some cases

  • Removed test for Pillow JPEG and PNG support, as the minimum supported version of Pillow now enforces this

  • OCRmyPDF now tests that the intended destination file is writable before proceeding

  • The test suite now requires pytest-helpers-namespace to run (but not install)

  • Significant code reorganization to make OCRmyPDF re-entrant and improve performance. All changes should be backward compatible for the v4.x series.

    • However, OCRmyPDF’s dependency “ruffus” is not re-entrant, so no Python API is available. Scripts should continue to use the command line interface.


  • Update documentation to confirm Python 3.6.0 compatibility. No code changes were needed, so many earlier versions are likely supported.


  • Fixed “decimal.InvalidOperation: quantize result has too many digits” for high DPI images


  • Fixed PDF/A creation with Ghostscript 9.20 properly

  • Fixed an exception on inline stencil masks with a missing optional parameter


  • Fixed a PDF/A creation issue with Ghostscript 9.20 (note: this fix did not actually work)


  • Fixed an issue where pages produced by the “hocr” renderer after a Tesseract timeout would be rotated incorrectly if the input page was rotated with a /Rotate marker

  • Fixed a file handle leak in LeptonicaErrorTrap that would cause a “too many open files” error for files around hundred pages of pages long when --deskew or --remove-background or other Leptonica based image processing features were in use, depending on the system value of ulimit -n

  • Ability to specify multiple languages for multilingual documents is now advertised in documentation

  • Reduced the file sizes of some test resources

  • 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


  • New feature --remove-background to detect and erase the background of color and grayscale images

  • Better documentation

  • Fixed an issue with PDFs that draw images when the raster stack depth is zero

  • ocrmypdf can now redirect its output to stdout for use in a shell pipeline

    • This does not improve performance since temporary files are still used for buffering

    • Some output validation is disabled in this mode


  • Fixed an issue (#100) with PDFs that omit the optional /BitsPerComponent parameter on images

  • Removed non-free file milk.pdf


  • Fixed an error (#90) caused by PDFs that use stencil masks properly

  • Fixed handling of PDFs that try to draw images or stencil masks without properly setting up the graphics state (such images are now ignored for the purposes of calculating DPI)


  • Fixed an issue with PDFs that store page rotation (/Rotate) in an indirect object

  • Integrated a few fixes to simplify downstream packaging (Debian)

    • The test suite no longer assumes it is installed

    • If running Linux, skip a test that passes Unicode on the command line

  • Added a test case to check explicit masks and stencil masks

  • Added a test case for indirect objects and linearized PDFs

  • Deprecated the shell script


  • Improvements to documentation


  • Fixed an issue where PDF pages that contained stencil masks would report an incorrect DPI and cause Ghostscript to abort

  • Implemented stdin streaming


  • ocrmypdf will now try to convert single image files to PDFs if they are provided as input (#15)

    • This is a basic convenience feature. It only supports a single image and always makes the image fill the whole page.

    • For better control over image to PDF conversion, use img2pdf (one of ocrmypdf’s dependencies)

  • New argument --output-type {pdf|pdfa} allows disabling Ghostscript PDF/A generation

    • pdfa is the default, consistent with past behavior

    • pdf provides a workaround for users concerned about the increase in file size from Ghostscript forcing JBIG2 images to CCITT and transcoding JPEGs

    • pdf preserves as much as it can about the original file, including problems that PDF/A conversion fixes

  • PDFs containing images with “non-square” pixel aspect ratios, such as 200x100 DPI, are now handled and converted properly (fixing a bug that caused to be cropped)

  • --force-ocr rasterizes pages even if they contain no images

    • supports users who want to use OCRmyPDF to reconstruct text information in PDFs with damaged Unicode maps (copy and paste text does not match displayed text)

    • supports reinterpreting PDFs where text was rendered as curves for printing, and text needs to be recovered

    • fixes issue #82

  • Fixes an issue where, with certain settings, monochrome images in PDFs would be converted to 8-bit grayscale, increasing file size (#79)

  • Support for Ubuntu 12.04 LTS “precise” has been dropped in favor of (roughly) Ubuntu 14.04 LTS “trusty”

    • Some Ubuntu “PPAs” (backports) are needed to make it work

  • Support for some older dependencies dropped

    • Ghostscript 9.15 or later is now required (available in Ubuntu trusty with backports)

    • Tesseract 3.03 or later is now required (available in Ubuntu trusty)

  • Ghostscript now runs in “safer” mode where possible


  • 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


  • More helpful error message for PDFs with version 4 security handler

  • Update usage instructions for Windows/Docker users

  • Fixed order of operations for matrix multiplication (no effect on most users)

  • Add a few leptonica wrapper functions (no effect on most users)


  • 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


  • --rotate-pages now only rotates pages when reasonably confidence in the orientation. This behavior can be adjusted with the new argument --rotate-pages-threshold

  • 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


  • Minor correction to Ghostscript output settings


  • Update install instructions

  • Provide a sRGB profile instead of using Ghostscript’s


  • Remove some verbose debug messages from v4.0.4

  • Fixed temporary that wasn’t being deleted

  • DPI is now calculated correctly for cropped images, along with other image transformations

  • Inline images are now checked during DPI calculation instead of rejecting the image


Released with verbose debug message turned on. Do not use. Skip to v4.0.5.


New features

  • Page orientations detected are now reported in a summary comment


  • Show stack trace if unexpected errors occur

  • Treat “too few characters” error message from Tesseract as a reason to skip that page rather than abort the file

  • Docker: fix blank JPEG2000 issue by insisting on Ghostscript versions that have this fixed



  • Fixed compatibility with Tesseract 3.04.01 release, particularly its different way of outputting orientation information

  • Improved handling of Tesseract errors and crashes

  • Fixed use of chmod on Docker that broke most test cases



  • Fixed a KeyError if tesseract fails to find page orientation information


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 fairly reliable but some false positives occur especially if there is not much text to work with. (#4)

  • Deskewing is now performed using Leptonica instead of unpaper. Leptonica is faster and more reliable at image deskewing than unpaper.


  • 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)

  • Fixed an issue where lossless reconstruction could misalign the graphics layer with respect to text layer if the page had been cropped such that its origin is not (0, 0) (#49)


  • Logging output is now much easier to read

  • --deskew is now performed by Leptonica instead of unpaper (#25)

  • libffi is now required

  • Some changes were made to the Docker and Travis build environments to support libffi

  • --pdf-renderer=tesseract now displays a warning if the Tesseract version is less than 3.04.01, the planned release that will include fixes to an important OCR text rendering bug in Tesseract 3.04.00. You can also manually install ./share/sharp2.ttf on top of pdf.ttf in your Tesseract tessdata folder to correct the problem.



  • Fixed #47 “convert() got and unexpected keyword argument ‘dpi’” by upgrading to img2pdf 0.2

  • Tweaked the Dockerfiles


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 of vector and raster content would see the vector content preserved. Images may still be transcoded during PDF/A conversion. (--deskew and --clean-final disable this mode, necessarily.)

  • New argument --tesseract-pagesegmode allows you to pass page segmentation arguments to Tesseract OCR. This helps for two column text and other situations that confuse Tesseract.

  • Added a new “polyglot” version of the Docker image, that generates Tesseract with all languages packs installed, for the polyglots among us. It is much larger.


  • JPEG transcoding quality is now 95 instead of the default 75. Bigger file sizes for less degradation.



  • Fixed bug that caused incorrect page size and DPI calculations on documents with mixed page sizes



  • 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 needed to implement support

  • Improved some error messages related to missing input files

  • Fixed #20: uppercase .PDF extension not accepted

  • Fixed an issue where OCRmyPDF failed to text that certain pages contained previously OCR’ed text, such as OCR text produced by Tesseract 3.04

  • Inserts /Creator tag into PDFs so that errors can be traced back to this project

  • Added new option --pdf-renderer=auto, to let OCRmyPDF pick the best PDF renderer. Currently it always chooses the ‘hocrtransform’ renderer but that behavior may change.

  • Set up Travis CI automatic integration testing


New features

  • Easier installation with a Docker container or Python’s pip package manager

  • Eliminated many external dependencies, so it’s easier to setup

  • Now installs ocrmypdf to /usr/local/bin or equivalent for system-wide access and easier typing

  • Improved command line syntax and usage help (--help)

  • Tesseract 3.03+ PDF page rendering can be used instead for better positioning of recognized text (--pdf-renderer tesseract)

  • PDF metadata (title, author, keywords) are now transferred to the output PDF

  • PDF metadata can also be set from the command line (--title, etc.)

  • Automatic repairs malformed input PDFs if possible

  • Added test cases to confirm everything is working

  • Added option to skip extremely large pages that take too long to OCR and are often not OCRable (e.g. large scanned maps or diagrams); other pages are still processed (--skip-big)

  • Added option to kill Tesseract OCR process if it seems to be taking too long on a page, while still processing other pages (--tesseract-timeout)

  • Less common colorspaces (CMYK, palette) are now supported by conversion to RGB

  • Multiple images on the same PDF page are now supported


  • New, robust rewrite in Python 3.4+ with ruffus pipelines

  • Now uses Ghostscript 9.14’s improved color conversion model to preserve PDF colors

  • OCR text is now rendered in the PDF as invisible text. Previous versions of OCRmyPDF incorrectly rendered visible text with an image on top.

  • All “tasks” in the pipeline can be executed in parallel on any available CPUs, increasing performance

  • The -o DPI argument has been phased out, in favor of --oversample DPI, in case we need -o OUTPUTFILE in the future

  • Removed several dependencies, so it’s easier to install. We no longer use:

  • Some new external dependencies are required or optional, compared to v2.x:

    • Ghostscript 9.14+

    • qpdf 5.0.0+

    • Unpaper 6.1 (optional)

    • some automatically managed Python packages

Release candidates^

  • rc9:

    • Fix #118: report error if ghostscript iccprofiles are missing

    • fixed another issue related to #111: PDF rasterized to palette file

    • add support image files with a palette

    • don’t try to validate PDF file after an exception occurs

  • rc8:

    • Fix #111: exception thrown if PDF is missing DocumentInfo dictionary

  • rc7:

    • fix error when installing direct from pip, “no such file ‘requirements.txt’”

  • rc6:

    • dropped libxml2 (Python lxml) since Python 3’s internal XML parser is sufficient

    • set up Docker container

    • fix Unicode errors if recognized text contains Unicode characters and system locale is not UTF-8

  • rc5:

    • dropped Java and JHOVE in favour of qpdf

    • improved command line error output

    • additional tests and bug fixes

    • tested on Ubuntu 14.04 LTS

  • rc4:

    • dropped MuPDF in favour of qpdf

    • fixed some installer issues and errors in installation instructions

    • improve performance: run Ghostscript with multithreaded rendering

    • improve performance: use multiple cores by default

    • bug fix: checking for wrong exception on process timeout

  • rc3: skipping version number intentionally to avoid confusion with Tesseract

  • rc2: first release for public testing to test-PyPI, Github

  • rc1: testing release process

Compatibility notes

  • ./ script is still available for now

  • Stacking the verbosity option like -vvv is no longer supported

  • The configuration file has been removed. Instead, you can feed a file to the arguments for common settings:

ocrmypdf input.pdf output.pdf @settings.txt

where settings.txt contains one argument per line, for example:

A. Merkel


  • 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.

  • --pdf-renderer tesseract will output files with an incorrect page size in Tesseract 3.03, due to a bug in Tesseract.

  • PDF files containing “inline images” are not supported and won’t be for the 3.0 release. Scanned images almost never contain inline images.

v2.2-stable (2014-09-29)

OCRmyPDF versions 1 and 2 were implemented as shell scripts. OCRmyPDF 3.0+ is a fork that gradually replaced all shell scripts with Python while maintaining the existing command line arguments. No one is maintaining old versions.

For details on older versions, see the final version of its release notes.