blob: 5f0f7163990df71cb812516f44a4ccad76a92d51 [file] [log] [blame]
#!/usr/bin/env python
# Copyright 2015 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Windows ICO file crusher.
Optimizes the PNG images within a Windows ICO icon file. This extracts all of
the sub-images within the file, runs any PNG-formatted images through, then packs them back into an ICO file.
NOTE: ICO files can contain both raw uncompressed BMP files and PNG files. This
script does not touch the BMP files, which means if you have a huge uncompressed
image, it will not get smaller. 256x256 icons should be PNG-formatted first.
(Smaller icons should be BMPs for compatibility with Windows XP.)
import argparse
import logging
import os
import StringIO
import sys
import ico_tools
def main(args=None):
if args is None:
args = sys.argv[1:]
parser = argparse.ArgumentParser(description='Crush Windows ICO files.')
parser.add_argument('files', metavar='ICO', type=argparse.FileType('r+b'),
nargs='+', help='.ico files to be crushed')
parser.add_argument('-o', dest='optimization_level', metavar='OPT', type=int,
help='optimization level')
parser.add_argument('--lint', dest='lint', action='store_true',
help='test the ICO file without modifying (set status '
'to 1 on error)')
parser.add_argument('-d', '--debug', dest='debug', action='store_true',
help='enable debug logging')
args = parser.parse_args()
if args.debug:
failed = False
for file in args.files:
buf = StringIO.StringIO(), os.SEEK_END)
old_length = file.tell(), os.SEEK_SET)
if args.lint:
for error in ico_tools.LintIcoFile(file):
logging.warning('%s: %s',, error)
# Any errors should cause this process to exit with a status of 1.
failed = True
ico_tools.OptimizeIcoFile(file, buf, args.optimization_level)
new_length = len(buf.getvalue())
# Always write (even if file size not reduced), because we make other fixes
# such as regenerating the AND mask.
if new_length >= old_length:'%s : Could not reduce file size.',
saving = old_length - new_length
saving_percent = float(saving) / old_length'%s : %d => %d (%d bytes : %d %%)',, old_length,
new_length, saving, int(saving_percent * 100))
return failed
if __name__ == '__main__':