This reverts commit 0a6a06346a.
The commit replaced the text to search for from ALICE to BOB, because
our OCR detection only caught "BOB FOOBAR" but missed "ALICE FOOBAR"
completely.
With the improvements to our OCR system this no longer is the case and
the test passes successfully with this reverted.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Cc: @shlevy
First of all, we're now using ImageMagick to improve the screenshot so
that Tesseract has an esier time to recognize the text. The resulting
image of this post-processing is a scaled up black-and-white version
with the backgrounds almost entirely removed and the text edges a bit
blurred, so the screen shots now more or less resemble an image from a
scanner rather. This is what Tesseract is trained for by default.
As mentioned in the previous commit we now also use Tesseract 4, which
further improves the quality of text recognition.
I've spent countless hours just to test different postprocessing
variants and testing what works best for our tests and this is the one
that worked best so far. It's certainly not perfect and I'd like to
avoid the scaling step but we're way better off than before.
In addition to this, the OCR process is now done without an intermediate
file, solely using pipes.
I've tested this using the following VM tests which have OCR enabled:
* nixos/tests/chromium.nix -A stable
* nixos/tests/emacs-daemon.nix
* nixos/tests/installer.nix -A luksroot
* nixos/tests/lightdm.nix
* nixos/tests/plasma5.nix
* nixos/tests/sddm.nix
All of the tests still succeed and comparing some of the recognition
results to the earlier results it now also detects a lot more text than
before this commit.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Tesseract 4 has got a new long short-term memory neural networking based
OCR engine which really helps a lot in terms of accuracy and our VM
tests.
I ran the new version across a bunch of different screenshots and
comparing the results to the 3.x branch and it really makes a big
difference, especially with various font rendering settings.
The only downside of this is that version 4 hasn't been released yet and
is in alpha state right now, but it will eventually get there and the
only solutions that came into my mind sticking to version 3 were really
sub-par:
* Use several passes with different color negation on the screenshots.
* Train Tesseract 3 specifically for screenshots. This is sub-par
because we'd need to do it for Tesseract 4 from scratch again.
* Change the test systems so that it specifically uses *only* OCR an
font when displaying. I've actually tried this but this also isn't
accurate enough with our default font rendering setup.
* Turn off special font rendering settings for our tests. In
conjunction with changing to an OCR font this might work but it won't
catch all the cases, because applications might use their own font
rendering.
Given that version 4 is faster[1] when it comes to OCR detection and also
the points just mentioned I think even using the alpha version just for
tests isn't going to hurt anybody.
[1]: https://github.com/tesseract-ocr/tesseract/wiki/4.0-Accuracy-and-Performance
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
This is from the commit message I've written for the upstream pull
request (jflesch/pyocr#62):
This is a bit more involved, because Tesseract 3.05.00 comes not
only with improvements but also with a few quirks we need to deal
with.
The first quirk is that the order arguments of the `tesseract'
command now matters and the list of configurations has to be at the
end of the command line. So we add a new attribute tesseract_flags
to the BaseBuilder class that contains a list of all the flags to
pass to `tesseract', the tesseract_configs attribute however remains
pretty much the same but now only really contains a list of configs
instead of being mixed with flag arguments.
Another quirk has to do with Leptonica >= 1.74 which Tesseract
3.05.00 now requires. Leptonica has special handling of files that
reside in /tmp and assumes that it's an internal temporary file of
Leptonica. In order to deal with it, we now run Tesseract in a
temporary directory, which contains the input/output files and use
the relative name of these files because Leptonica only searches for
path names beginning with /tmp.
Fortunately the last item we need to address is not really a quirk,
but an API change. In Tesseract 3.05.00 there is now a new function
called TessBaseAPIDetectOrientationScript(), which doesn't fill the
OSResults object anymore but now allows to pass the values we're
interested in directly by reference. We need to use this new
function because the old function TessBaseAPIDetectOS() now *always*
returns false.
I've tested this specifically on NixOS and in conjunction with Paperwork
(the only package that's using pyocr so far) and all the tests of the
dependency chain are now succeeding. However, I didn't do manual tests
of Paperwork though.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Upstream changes for version 0.4.5:
* Clean up exceptions raised when OCR fails:
* Now, all tools raise only exceptions inheriting from
pyocr.PyocrException
* There is now one and only one TesseractError (shared between
pyocr.libtesseract and pyocr.tesseract)
Upstream changes for version 0.4.6:
* hOCR outputs: Generate valid XHTML files
The full upstream changelog can be found at:
https://github.com/jflesch/pyocr/blob/master/ChangeLog
Note that because of the version bump of Tesseract neither version 0.4.4
nor version 0.4.6 succeed to build, so we need to fix this up soon.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Upstream changelog:
* Made some fine tuning to the hOCR output.
* Added TSV as another optional output format.
* Fixed ABI break introduced in 3.04.00 with the AnalyseLayout()
method.
* text2image tool - Enable all OpenType ligatures available in a font.
This feature requires Pango 1.38 or newer.
* Training tools - Replaced asserts with tprintf() and exit(1).
* Fixed Cygwin compatibility.
* Improved multipage tiff processing.
* Improved the embedded pdf font (pdf.ttf).
* Enable selection of OCR engine mode from command line.
* Changed tesseract command line parameter '-psm' to '--psm'.
* Added new C API for orientation and script detection, removed the old
one.
* Increased minimum autoconf version to 2.59.
* Removed dead code.
* Fixed many compiler warning.
* Fixed memory and resource leaks.
* Fixed some issues with the 'Cube' OCR engine.
* Fixed some openCL issues.
* Added option to build Tesseract with CMake build system.
* Implemented CPPAN support for easy Windows building.
The upstream URL of the change log is:
https://github.com/tesseract-ocr/tesseract/releases/tag/3.05.00
Tested by building against the following packages that directly depend
on it:
* vapoursynth (with ocrSupport = true)
* pyocr (fails)
* vobsub2srt
Also tested against the following NixOS VM tests that have OCR enabled:
* nixos/tests/chromium.nix -A stable
* nixos/tests/emacs-daemon.nix
* nixos/tests/installer.nix -A luksroot
* nixos/tests/lightdm.nix
* nixos/tests/plasma5.nix
* nixos/tests/sddm.nix
All of the packages and tests except pyocr build/succeed on
x86_64-linux.
Fixing pyocr is outside of the scope of this commit and will happen very
soon.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
The changes are a bit too big to include it here in the commit message,
so if you want the details of what changed, please visit this URL:
http://leptonica.org/source/version-notes.html
I have also provided openjpeg, giflib and libwebp as dependencies so
that Leptonica is able to read/write those file formats.
Additionally I've added a patch that uses pkgconfig to resolve all
dependencies (except giflib), because unlike AC_CHECK_LIB() the
PKG_CHECK_MODULES() macro defines *_LIBS variables to include the linker
search path.
Unfortunately that patch alone is not enough, because the *_LIBS
variable are substituted by the upstream configure.ac to *not* include
the linker search paths, so we need to remove the AC_SUBST() calls
within PKG_CHECK_MODULES().
The only dependency that's not yet using PKG_CHECK_MODULES() is giflib,
because giflib doesn't have a pkg-config description file, therefore
we're using substituteInPlace to insert the linker search path after the
lept.pc file was generated by configure.
Another thing that we no longer need is the dependency on libpng version
1.2, because Leptonica now also works with more recent libpng versions.
Tested by building the package itself and also the following packages
that immediately depend on leptonica:
* k2pdfopt
* tesseract
* jbig2enc
All of these packages succeeded to build on x86_64-linux.
The main reason why I'm bumping Leptonica to version 1.74.1 is that we
need at least version 1.74 to bump Tesseract to the latest upstream
version.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
I've removed that attribute in 68bc260ca2,
because the language files no longer were distributed as seperate files,
but if we for example only want to use the English training data, the
closure size of Tesseract gets quite large (around 1.2 GB), which is a
bit much just to be able to run NixOS VM tests.
For this reason I've also switched the VM tests back to using only the
English language.
Tested using the following VM tests (the ones that have OCR enabled) on
x86_64-linux:
* nixos/tests/chromium.nix -A stable
* nixos/tests/emacs-daemon.nix
* nixos/tests/installer.nix -A luksroot
* nixos/tests/lightdm.nix
* nixos/tests/plasma5.nix
* nixos/tests/sddm.nix
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
* notmuch: fix homepage and notmuch-mutt license
notmuch-mutt's license is GPLv3. might have been changed when it was upstreamed.
* fix scheme
* fix typo in url
* fix field alignment
* use with to make statements shorter
* tig: 2.2 -> 2.2.1
Also move to different project URLs, as requested in
https://github.com/jonas/tig/releases/tag/tig-2.2.1
* tig: fix fetching mechanism
Rework the dependencies to allow use of fetchFromGitHub.
