Add -f to force generation of the background image at the desired
oversample resolution. Our new behavior is to only send the oversampled
image to Tesseract while leaving the main page intact unless asked to
deskew, clean, etc.
Switched from Ubuntu to debian:stretch because stretch has more recent
versions of our binary packages and starts smaller. In particular,
stretch has both pillow==2.9.0 and reportlab==3.2.0 available as system
packages which saves the considerable hassle of install a toolchain.
Instead, a pyvenv is set up with access to system's site-packages (note:
needs two steps), making the binary-dependent packages available. Then
the remaining packages are installed into the pyvenv with --no-cache-dir
to avoid saving files. And there we are.
Image is still very large (>500 MB), but programs like reportlab require
font rendering capabilities so they pull in large portions of the Linux
graphics stack. Not much will shrink that.
fileinput is supposed to save time in these cases but it's not capable
of doing both in-place rewrites and working with a non-ascii encoding.
This was not noticed until characters outside of ASCII were picked up
by tesseract and saved in a HOCR file. Rework some surrounding code as
well and add multilingual test cases.
ruffus swallows the return code if the process of handling an exception
we hit an error in ruffus' own code, which can happen. So pick through
its error stack and find out if there's an interesting return code in
there. Had to use eval() of all things.
Also suppress the stack trace for normal error conditions that don't
need one.
Some versions of tesseract installed by homebrew end up without a
functional tessdata folder, and tesseract is not helpful in this
situation, so add a new test to make sure our output is at least
indicative of the problem.
In the process of properly handling return codes I discovered
test_override_metadata triggers a NPE inside JHOVE probably due to the
Unicode character checking. This could be specific to my JRE (1.6.0_65,
Oracle) but it's probably JHOVE's fault. A valid PDF/A (per Acrobat)
is still generated.
It revealed a regression - return code not the same as v2.x for invalid
PDF/A. It's also not easy to get the return code out of ruffus. Will
need to tweak the final step of the pipeline.
Although the real issue was that the ruffus pipeline cannot be executed
twice in the same process due to its reliance on global variables.
The new OO pipeline in ruffus 2.6 would be one resolution that would
allow for more comprehensive testing as opposed to farming out the
execution to subprocess and inspecting the results, as is currently
done.
