OCRmyPDF/ocrmypdf/exec/ghostscript.py
2016-12-10 15:34:00 -08:00

83 lines
2.7 KiB
Python

#!/usr/bin/env python3
# © 2015 James R. Barlow: github.com/jbarlow83
from tempfile import NamedTemporaryFile
from subprocess import Popen, PIPE, STDOUT, check_call
from shutil import copy
from . import get_program
from ..pdfa import SRGB_ICC_PROFILE
def rasterize_pdf(input_file, output_file, xres, yres, raster_device, log,
pageno=1):
with NamedTemporaryFile(delete=True) as tmp:
args_gs = [
get_program('gs'),
'-dQUIET',
'-dSAFER',
'-dBATCH',
'-dNOPAUSE',
'-sDEVICE=%s' % raster_device,
'-dFirstPage=%i' % pageno,
'-dLastPage=%i' % pageno,
'-o', tmp.name,
'-r{0}x{1}'.format(str(round(xres)), str(round(yres))),
input_file
]
p = Popen(args_gs, close_fds=True, stdout=PIPE, stderr=STDOUT,
universal_newlines=True)
stdout, _ = p.communicate()
if 'error' in stdout:
log.error(stdout) # Ghostscript puts errors in stdout
else:
log.debug(stdout)
if p.returncode == 0:
copy(tmp.name, output_file)
else:
log.error('Ghostscript rendering failed')
def generate_pdfa(pdf_pages, output_file, log, threads=1):
with NamedTemporaryFile(delete=True) as gs_pdf:
args_gs = [
get_program("gs"),
"-dQUIET",
"-dBATCH",
"-dNOPAUSE",
'-dNumRenderingThreads=' + str(threads),
"-sDEVICE=pdfwrite",
"-dAutoRotatePages=/None",
"-sColorConversionStrategy=/RGB",
"-sProcessColorModel=DeviceRGB",
"-dJPEGQ=95",
"-dPDFA=2",
"-dPDFACompatibilityPolicy=1",
"-sOutputFile=" + gs_pdf.name,
]
args_gs.extend(pdf_pages)
p = Popen(args_gs, close_fds=True, stdout=PIPE, stderr=STDOUT,
universal_newlines=True)
stdout, _ = p.communicate()
if 'error' in stdout:
log.error(stdout)
elif 'overprint mode not set' in stdout:
# Unless someone is going to print PDF/A documents on a
# magical sRGB printer I can't see the removal of overprinting
# being a problem....
log.debug(
"Ghostscript had to remove PDF 'overprinting' from the "
"input file to complete PDF/A conversion. "
)
else:
log.debug(stdout)
if p.returncode == 0:
# Ghostscript does not change return code when it fails to create
# PDF/A - check PDF/A status elsewhere
copy(gs_pdf.name, output_file)
else:
log.error('Ghostscript PDF/A failed')