menekis/OCRmyPDF
Public Access
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Revise parameter validation for output-type, pdf-renderer, lang

Browse Source
This commit is contained in:
James R. Barlow
2018-05-10 14:53:22 -07:00
parent b8f3ead541
commit aef043db0b
1 changed files with 45 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/ocrmypdf/__main__.py
+45 -33
View File
@@ -351,21 +351,58 @@ def check_options_languages(options, _log):
def check_options_output(options, log):
# We have these constraints to check for.
# 1. Ghostscript < 9.20 mangles multibyte Unicode
# 2. Tesseract < 3.05 embeds an older version of GlyphlessFont with which
# no version of Ghostscript handles correctly.
# 3. hocr doesn't work on non-Latin languages (so don't select it)
languages = set(options.language)
is_latin = languages.issubset(HOCR_OK_LANGS)
if options.pdf_renderer == 'hocr' and not is_latin:
msg = (
"The 'hocr' PDF renderer is known to cause problems with one "
"or more of the languages in your document. Use "
"--pdf-renderer auto (the default) to avoid this issue.")
log.warning(msg)
if ghostscript.version() < '9.20' \
and options.output_type != 'pdf' \
and not is_latin:
# https://bugs.ghostscript.com/show_bug.cgi?id=696874
# Ghostscript < 9.20 fails to encode multibyte characters properly
msg = (
"The installed version of Ghostscript does not work correctly "
"with the OCR languages you specified. Use --output-type pdf or "
"upgrade to Ghostscript 9.20 or later to avoid this issue.")
msg += "Found Ghostscript {}".format(ghostscript.version())
log.warning(msg)
# Decide on what renderer to use
if options.pdf_renderer == 'auto':
if tesseract.version() < '3.05' \
and options.output_type.startswith('pdfa'):
and options.output_type.startswith('pdfa') \
and is_latin:
options.pdf_renderer = 'hocr'
else:
options.pdf_renderer = 'sandwich'
if options.pdf_renderer == 'sandwich' \
and tesseract.version() < '3.05' \
and options.output_type.startswith('pdfa'):
log.warning(
"For best results use --pdf-renderer=sandwich "
"--output-type=pdf to disable PDF/A generation via "
"Ghostscript, which is known to corrupt the OCR text of "
"some PDFs produced your version of Tesseract.")
and tesseract.version() < '3.05':
msg = (
"Ghostscript will corrupt the OCR text of PDFs produced by "
"Tesseract 3.04.xx and older. For best results, upgrade to a "
"newer release of Tesseract. "
)
if options.output_type.startswith('pdfa'):
msg += (
"The argument --output-type=pdfa* requires Ghostscript, so "
"the PDF will be invalid. If you cannot upgrade Tesseract, "
"use --output-type=pdf.")
raise MissingDependencyError(msg)
log.warning(msg)
lossless_reconstruction = False
if options.pdf_renderer in ('hocr', 'sandwich'):
@@ -404,31 +441,6 @@ def check_options_ocr_behavior(options, log):
None,
"Error: --force-ocr and --skip-text are mutually incompatible.")
languages = set(options.language)
if options.pdf_renderer == 'hocr' and \
not languages.issubset(HOCR_OK_LANGS):
msg = (
"The 'hocr' PDF renderer is known to cause problems with one "
"or more of the languages in your document. ")
if tesseract.has_textonly_pdf():
msg += (
"Use --pdf-renderer auto (the default) to avoid this issue.")
else:
msg += (
"Use --pdf-renderer sandwich --output-type pdf to avoid "
"this issue")
log.warning(msg)
elif ghostscript.version() < '9.20' and \
not languages.issubset(HOCR_OK_LANGS) \
and options.output_type != 'pdf':
msg = (
"The installed version of Ghostscript does not work correctly "
"with the OCR languages you specified. Use --output-type pdf or "
"upgrade to Ghostscript 9.20 or later to avoid this issue.")
msg += "Found Ghostscript {}".format(ghostscript.version())
log.warning(msg)
def check_options_advanced(options, log):
if options.tesseract_oem and not tesseract.v4():