tools/compress-pngs.py

   1 #!/usr/bin/env python3
   2 #
   3 # compress-pngs.py - Compress PNGs
   4 #
   5 # By Gerald Combs <gerald@wireshark.org
   6 #
   7 # SPDX-License-Identifier: GPL-2.0-or-later
   8 #
   9 '''Run various compression and optimization utilities on one or more PNGs'''
  10
  11 import argparse
  12 import concurrent.futures
  13 import shutil
  14 import subprocess
  15 import sys
  16
  17 PNG_FILE_ARG = '%PNG_FILE_ARG%'
  18
  19 def get_compressors():
  20     # Add *lossless* compressors here.
  21     compressors = {
  22         # https://github.com/shssoichiro/oxipng
  23         'oxipng': { 'args': ['--opt', 'max', '--strip', 'safe', PNG_FILE_ARG] },
  24         # http://optipng.sourceforge.net/
  25         'optipng': { 'args': ['-o3', '-quiet', PNG_FILE_ARG] },
  26         # https://github.com/amadvance/advancecomp
  27         'advpng': { 'args': ['--recompress', '--shrink-insane', PNG_FILE_ARG] },
  28         # https://github.com/amadvance/advancecomp
  29         'advdef': { 'args': ['--recompress', '--shrink-insane', PNG_FILE_ARG] },
  30         # https://pmt.sourceforge.io/pngcrush/
  31         'pngcrush': { 'args': ['-q', '-ow', '-brute', '-reduce', '-noforce', PNG_FILE_ARG, 'pngcrush.$$$$.png'] },
  32         # https://github.com/fhanau/Efficient-Compression-Tool
  33         'ect': { 'args': ['-5', '--mt-deflate', '--mt-file', '-strip', PNG_FILE_ARG]}
  34     }
  35     for compressor in compressors:
  36         compressor_path = shutil.which(compressor)
  37         if compressor_path:
  38             compressors[compressor]['path'] = compressor_path
  39     return compressors
  40
  41
  42 def compress_png(png_file, compressors):
  43     for compressor in compressors:
  44         if not compressors[compressor].get('path', False):
  45             continue
  46
  47         args = compressors[compressor]['args']
  48         args = [arg.replace(PNG_FILE_ARG, png_file) for arg in args]
  49
  50         try:
  51             compress_proc = subprocess.run([compressor] + args)
  52         except Exception:
  53             print('{} returned {}:'.format(compressor, compress_proc.returncode))
  54
  55
  56 def main():
  57     parser = argparse.ArgumentParser(description='Compress PNGs')
  58     parser.add_argument('--list', action='store_true',
  59                         help='List available compressors')
  60     parser.add_argument('png_files', nargs='*', metavar='png file', help='Files to compress')
  61     args = parser.parse_args()
  62
  63     compressors = get_compressors()
  64
  65     c_count = 0
  66     for compressor in compressors:
  67         if 'path' in compressors[compressor]:
  68             c_count += 1
  69
  70     if c_count < 1:
  71         sys.stderr.write('No compressors found\n')
  72         sys.exit(1)
  73
  74     if args.list:
  75         for compressor in compressors:
  76             path = compressors[compressor].get('path', 'Not found')
  77             print('{}: {}'.format(compressor, path))
  78         sys.exit(0)
  79
  80     with concurrent.futures.ProcessPoolExecutor() as executor:
  81         futures = []
  82         for png_file in args.png_files:
  83             print('Compressing {}'.format(png_file))
  84             futures.append(executor.submit(compress_png, png_file, compressors))
  85         concurrent.futures.wait(futures)
  86
  87
  88 if __name__ == '__main__':
  89     main()