This commit includes an optional work around for limitations of the
PDF.js viewer described in
https://github.com/jbarlow83/OCRmyPDF/issues/133. Here is explicitly
add an addition space to text elements before drawing them on the PDF
canvas when using the HOCR renderer. This option does not apply to
other pdf renderers in OCRmyPDF and is turned off by default.
Previously we threw an exception if the output name was a directory (only after doing OCR) and would trigger a PermissionError on trying to flip permission bits of /dev/null due to shutil.copyfile implementation. Instead of copying file use shutil.copyfileobj which should also respect umask etc.
Omitted French because the rare 'oe' and 'ÿ' glyphs are not in Latin-1.
Basically steer people away from HOCR renderer but avoid a potential
disruptive behavior change.
Tesseract 3.05.01 backported the textonly_pdf=1 which allows the use
of this superior PDF renderer prior to 4.00 alpha. This means that
the tess4 name is no longer accurate, so call it a sandwich because of
its merge-preserve characteristic. Preserve the tess4 name. Fix the
documentation and tests to reflect this.
Make it the default, because it’s better. It does not have the issues
the “tesseract” renderer does prior to Tess 3.05.00 with rendering
PDFs that Ghostscript corrupts, and it produces better output without
re-rastering.
Deprecate some old stuff to avoid the test suite growing obscenely
large.
The 4th argument of re.sub() is maximum number of substitutions,
not flags.
Moreover, re.MULTILINE affects only semantics of ^ and $,
so it wouldn't have any effect on this regular expression.
Ghostscript 9.21 does not seem to accept Unicode above U+FFFF. Previous
versions did, but it now exits with a rangecheck error (-15).
Reject on the command line for now. Complete fix would also need to
check input PDF’s metadata.