chinkorize.py

import sys,Image
#needs pil

img = Image.open(sys.argv[1])
y, cr, cb = img.convert("YCbCr").split()
for px in range(0, img.size[0]):
    for py in range(0, img.size[1]):
        #rgb = img.getpixel((px,py))
        yy = y.getpixel((px,py))
        cr.putpixel((px,py), 110)
        cb.putpixel((px,py), 159)
        # process
    #print ""    
img = Image.merge("YCbCr", (y, cr, cb)).convert("RGB")
img.show()