from PIL import Image

import os


for filename in os.listdir(r'c:/image/png'):
  img = Image.open('c:/image/png/'+filename)
  img = img.convert("RGBA")
  print('c:/image/png/'+filename)
  pixdata = img.load()


  for y in xrange(img.size[1]):
    for x in xrange(img.size[0]):
      if pixdata[x,y][0]>220 and pixdata[x,y][1]>220 and pixdata[x,y][2]>220 and pixdata[x,y][3]>220:
        pixdata[x, y] = (255, 255, 255, 0)
  img.save("c:/image/pngNew/"+filename, "PNG")