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>
49cf934642