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#!/usr/bin/env python
# Copyright © 2010-2021 Jakub Wilk <jwilk@jwilk.net>
# Copyright © 2022-2024 FriedrichFroebel
#
# This file is part of djvulibre-python.
#
# djvulibre-python is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 2 as published by
# the Free Software Foundation.
#
# djvulibre-python is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
# more details.
import argparse
import os
import sys
try:
import cairo # pycairo
except ImportError:
import cairocffi as cairo
import djvu.decode
import numpy
CAIRO_PIXEL_FORMAT = cairo.FORMAT_ARGB32
DJVU_PIXEL_FORMAT = djvu.decode.PixelFormatRgbMask(0xFF0000, 0xFF00, 0xFF, bpp=32)
DJVU_PIXEL_FORMAT.rows_top_to_bottom = 1
DJVU_PIXEL_FORMAT.y_top_to_bottom = 0
class Context(djvu.decode.Context):
def handle_message(self, message):
if isinstance(message, djvu.decode.ErrorMessage):
print(message, file=sys.stderr)
# Exceptions in handle_message() are ignored, so sys.exit()
# wouldn't work here.
os._exit(1)
def process(self, djvu_path, png_path, mode):
document = self.new_document(djvu.decode.FileURI(djvu_path))
document.decoding_job.wait()
for page in document.pages:
page_job = page.decode(wait=True)
width, height = page_job.size
rect = (0, 0, width, height)
bytes_per_line = cairo.ImageSurface.format_stride_for_width(CAIRO_PIXEL_FORMAT, width)
assert bytes_per_line % 4 == 0
color_buffer = numpy.zeros((height, bytes_per_line // 4), dtype=numpy.uint32)
page_job.render(mode, rect, rect, DJVU_PIXEL_FORMAT, row_alignment=bytes_per_line, buffer=color_buffer)
mask_buffer = numpy.zeros((height, bytes_per_line // 4), dtype=numpy.uint32)
if mode == djvu.decode.RENDER_FOREGROUND:
page_job.render(djvu.decode.RENDER_MASK_ONLY, rect, rect, DJVU_PIXEL_FORMAT, row_alignment=bytes_per_line, buffer=mask_buffer)
mask_buffer <<= 24
color_buffer |= mask_buffer
color_buffer ^= 0xFF000000
surface = cairo.ImageSurface.create_for_data(color_buffer, CAIRO_PIXEL_FORMAT, width, height)
surface.write_to_png(png_path)
# Multi-page documents are not yet supported:
break
def main():
parser = argparse.ArgumentParser()
parser.set_defaults(mode=djvu.decode.RENDER_COLOR)
group = parser.add_mutually_exclusive_group()
group.add_argument('--foreground', dest='mode', action='store_const', const=djvu.decode.RENDER_FOREGROUND)
group.add_argument('--background', dest='mode', action='store_const', const=djvu.decode.RENDER_BACKGROUND)
group.add_argument('--mask', dest='mode', action='store_const', const=djvu.decode.RENDER_MASK_ONLY)
parser.add_argument('djvu_path', metavar='DJVU-FILE')
parser.add_argument('png_path', metavar='PNG-FILE')
options = parser.parse_args(sys.argv[1:])
context = Context()
context.process(options.djvu_path, options.png_path, options.mode)
if __name__ == '__main__':
main()
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