OCRmyPDF uses `semantic versioning <http://semver.org/>`_ for its command line interface.
The OCRmyPDF package itself does not contain a public API, although it is fairly stable and breaking changes are usually timed with a major release. A future release will clearly define the stable public API.
- PyMuPDF is now an optional but recommended dependency, to alleviate installation difficulties on platforms that have less access to PyMuPDF than the author anticipated. Install OCRmyPDF with ``pip install ocrmypdf[fitz]`` to use it to its full potential.
- Fix ``FileExistsError`` that could occur if OCR timed out while it was generating the output file. (`#218 <https://github.com/jbarlow83/OCRmyPDF/issues/218>`_)
- Fix 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.)
- Fix "RuntimeError: invalid key in dict" when table of contents/bookmarks titles contained the character ``)``. (`#239 <https://github.com/jbarlow83/OCRmyPDF/issues/239>`_)
- OCRmyPDF now depends on `PyMuPDF <https://pymupdf.readthedocs.io/en/latest/installation/>`_. Including PyMuPDF is the primary reason for the change to GPLv3.
+ 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.
- 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 <https://github.com/jbarlow83/OCRmyPDF/issues/233>`_, `#232 <https://github.com/jbarlow83/OCRmyPDF/issues/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 <https://github.com/jbarlow83/OCRmyPDF/issues/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 <https://github.com/jbarlow83/OCRmyPDF/issues/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 <https://github.com/jbarlow83/OCRmyPDF/issues/217>`_)
- Fixed an issue that caused poor CPU utilization on machines more than 4 cores when running Tesseract 4. (Related to issue `#217 <https://github.com/jbarlow83/OCRmyPDF/issues/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 <https://github.com/jbarlow83/OCRmyPDF/issues/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.
- Fix issue `#219 <https://github.com/jbarlow83/OCRmyPDF/issues/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``
- 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.
- 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.
- Fix 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
- Fix a few parameter validation checks for ``-output-type pdfa-1`` and ``pdfa-2``
- Fix issue `#181 <https://github.com/jbarlow83/OCRmyPDF/issues/181>`_: fix final merge failure for PDFs with more pages than the system file handle limit (``ulimit -n``)
- Fix issue `#200 <https://github.com/jbarlow83/OCRmyPDF/issues/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.
- Fix 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 <https://github.com/jbarlow83/OCRmyPDF/issues/200>`_ cause qpdf to infinite-loop
- Address issue `#140 <https://github.com/jbarlow83/OCRmyPDF/issues/140>`_: if Tesseract outputs invalid UTF-8, escape it and print its message instead of aborting with a Unicode error
- 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 <https://github.com/jbarlow83/OCRmyPDF/issues/165>`_)
- Using a non Latin-1 language with the "hocr" renderer now warns about possible OCR quality and recommends workarounds (`#176 <https://github.com/jbarlow83/OCRmyPDF/issues/176>`_)
- Output file path added to error message when that location is not writable (`#175 <https://github.com/jbarlow83/OCRmyPDF/issues/175>`_)
- 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 issue `#169 <https://github.com/jbarlow83/OCRmyPDF/issues/169>`_, exception due to failure to create sidecar text files on some versions of Tesseract 3.04, including the jbarlow83/ocrmypdf Docker image
- 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 <https://github.com/jbarlow83/OCRmyPDF/issues/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 <https://github.com/jbarlow83/OCRmyPDF/issues/163>`_.
- Removed the command line parameters ``-n`` and ``--just-print`` since they have not worked for some time (reported as Ubuntu bug `#1687308 <https://bugs.launchpad.net/ubuntu/+source/ocrmypdf/+bug/1687308>`_)
- Fixed issue `#156 <https://github.com/jbarlow83/OCRmyPDF/issues/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 issue `#158 <https://github.com/jbarlow83/OCRmyPDF/issues/158>`_, ocrmypdf now stops and terminates if Ghostscript fails on an intermediate step, as it is not possible to proceed.
- Fixed issue `#160 <https://github.com/jbarlow83/OCRmyPDF/issues/160>`_, exception thrown on certain invalid arguments instead of error message
- Fixed issue `#154 <https://github.com/jbarlow83/OCRmyPDF/issues/154>`_, KeyError '/Contents' when searching for text on blank pages that have no /Contents record. Note: incomplete fix for this issue.
- Fix ``--skip-big`` raising an exception if a page contains no images (`#152 <https://github.com/jbarlow83/OCRmyPDF/issues/152>`_) (thanks to @TomRaz)
- Fix an issue where pages with no images might trigger "cannot write mode P as JPEG" (`#151 <https://github.com/jbarlow83/OCRmyPDF/issues/151>`_)
- 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
- Fix issue `#147 <https://github.com/jbarlow83/OCRmyPDF/issues/147>`_. ``--pdf-renderer tess4 --clean`` will produce an oversized page containing the original image in the bottom left corner, due to loss DPI information.
- Fix issue `#137 <https://github.com/jbarlow83/OCRmyPDF/issues/137>`_, proportions of images with a non-square pixel aspect ratio would be distorted in output for ``--force-ocr`` and some other combinations of flags
- Exotic PDFs containing "Form XObjects" are now supported (issue `#134 <https://github.com/jbarlow83/OCRmyPDF/issues/134>`_; PDF reference manual 8.10), and images they contain are taken into account when determining the resolution for rasterizing
- 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
+ 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
- To prevent a `TIFF output error <https://github.com/python-pillow/Pillow/issues/2206>`_ 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 setup.py to deal with issues in the v4.4 release
+ 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 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
- 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)
+``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 an issue where, with certain settings, monochrome images in PDFs would be converted to 8-bit grayscale, increasing file size (`#79 <https://github.com/jbarlow83/OCRmyPDF/issues/79>`_)
- 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
-``--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
fairly reliable but some false positives occur especially if there is not much text to work with. (`#4 <https://github.com/jbarlow83/OCRmyPDF/issues/4>`_)
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 <https://github.com/fritz-hh/OCRmyPDF/blob/7fd3dbdf42ca53a619412ce8add7532c5e81a9d1/RELEASE_NOTES.md>`_.
