putpixel

from PIL import Image

img = Image.open("D:\Python27\ggg.gif")
(w,h) = img.size
im=img.convert("RGBA")

for i in xrange(w):
    for j in xrange(h):
        pos=(i,j)
        rgb = im.getpixel(pos)

        if rgb == (255,255,255,255):
            im.putpixel((i,j),(0,0,0,0))

im.save('D:\\Python27\\ggg888.gif')

#(r,g,b) = rgb

'''
        if(b > g and b > r):
            b=213
            g=192
            r=180
        img.putpixel((i,j), (000,000,000))

'''
#im.show()

#p.save('D:\\Python27\\mask6.gif')