bin/diff-pdf-page.py

   1 #!/usr/bin/env python3
   2 #
   3 # This Source Code Form is subject to the terms of the Mozilla Public
   4 # License, v. 2.0. If a copy of the MPL was not distributed with this
   5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   6 #
   7 # Diffs two PDF pages: a reference and our own output. Red output means some to fix: the amount of
   8 # red is meant to reduce as fixing progresses. Sample usage:
   9 #
  10 # bin/diff-pdf-page.py reference.pdf test.pdf diff.png
  11 #
  12 # using the ImageMagick tooling
  13
  14 import argparse
  15 import tempfile
  16 import subprocess
  17
  18 def run(argv):
  19     print(" ".join(argv))
  20     subprocess.run(argv, check=True)
  21
  22 def main():
  23     parser = argparse.ArgumentParser(description="Diffs two PDF pages, first is painted red instead of black, the second is painted on top of the first.")
  24     parser.add_argument("-d", "--density", default="384")
  25     parser.add_argument("-p", "--page", default="0")
  26     parser.add_argument("a_pdf")
  27     parser.add_argument("b_pdf")
  28     parser.add_argument("diff_png")
  29     args = parser.parse_args()
  30
  31     CONVERT_CMD="convert" # use "magick" if Windows has installed ImageMagick and GhostScript
  32
  33     a_png = tempfile.NamedTemporaryFile(suffix=".png")
  34     a_pdf = args.a_pdf + "[" + args.page + "]"
  35     run([CONVERT_CMD, "-density", args.density, a_pdf, "-colorspace", "RGB", "-transparent", "white", "-fuzz", "95%", "-fill", "red", "-opaque", "black", a_png.name])
  36     b_png = tempfile.NamedTemporaryFile(suffix=".png")
  37     b_pdf = args.b_pdf + "[" + args.page + "]"
  38     run([CONVERT_CMD, "-density", args.density, b_pdf, "-colorspace", "RGB", "-transparent", "white", b_png.name])
  39     run([CONVERT_CMD, a_png.name, b_png.name, "-composite",  "-background", "white", "-flatten", args.diff_png])
  40
  41 if __name__ == "__main__":
  42     main()
  43
  44 # vim:set shiftwidth=4 softtabstop=4 expandtab: