在Python中使用pngquant压缩png图片的教程

'''
pngquant.py
use pngquant to reduces png file size
Ruoqian, Chen<piao.polar@gmail.com> 

----------
2015/4/3
1. del option --quality=50-90, special pic need skip can config in lod ini

  lod ini format:

[PixelFormat]
map_01.png=0

  0 means skip in file

----------
2015/4/2
1. desDir can be the same to srcDir, or another dir
2. lod ini config can be not exist

----------
2015/3/31
create
'''

import os
import os.path
import sys
import ConfigParser
import string

PngquantExe="pngquant"

thisFilePath = sys.path[0];

print "this py file in dir : " + thisFilePath

projectPath = thisFilePath + "/../CMWar_2dx/CMWar_2dx/";
srcResDir = "Resources/";
dstResDir = "Resources/";

lodIniPath = projectPath + srcResDir + "ini/pic.ini"
keepOrgPaths = [];
if os.path.exists(lodIniPath):
  config = ConfigParser.SafeConfigParser()
  config.read(lodIniPath)
  section = "PixelFormat";
  options = config.options(section)
  for option in options:
    value = string.atoi(config.get(section, option))
    if not value:
      keepOrgPaths.append(option);

print keepOrgPaths

srcResPath = projectPath + srcResDir;

pngCount = 0;
transCount = 0;

#pngquant --force --skip-if-larger --ext .png --quality 50-90 --speed 1

for parent,dirnames,filenames in os.walk(srcResPath):
  print "----- process Dir " + parent
  dstDir = parent.replace(srcResDir, dstResDir)
  if not os.path.exists(dstDir):
    os.makedirs(dstDir)
  for filename in filenames:
    if os.path.splitext(filename)[1] == '.png':
      pngCount += 1;
      srcFilePath = os.path.join(parent, filename);
      dstFilePath = os.path.join(dstDir, filename);
      tmpFilePath = dstFilePath + ".tmp";

      if filename in keepOrgPaths:
        print "----- keep ----- " + filename;
      else:
#        print "----- process ----- " + filename;
#        cmd = "\"" + PngquantExe + "\"" + " --force --speed=1 --quality=50-90 -v " + srcFilePath + " -o " + tmpFilePath;
        cmd = "\"" + PngquantExe + "\"" + " --force --speed=1 " + srcFilePath + " -o " + tmpFilePath;
#        print cmd;
        os.system(cmd)
        if os.path.exists(tmpFilePath):
          sizeNew = os.path.getsize(tmpFilePath);
          sizeOld = os.path.getsize(srcFilePath);
          if sizeNew < sizeOld:
            open(dstFilePath, "wb").write(open(tmpFilePath, "rb").read())
            transCount += 1;
          os.remove(tmpFilePath)
      if not os.path.exists(dstFilePath):
        open(dstFilePath, "wb").write(open(srcFilePath, "rb").read())

print "Done. Trans Pngs: %d/%d" %(transCount, pngCount)