from PIL import Image
import sys

if len(sys.argv) != 2:
    print "Usage: solvesteg.py filename"
    exit(1)

img = Image.open(sys.argv[1], "r")
pix = img.load()
width = img.size[0]
height = img.size[1]

new_img = Image.new("L", (width, height))
new_pix = new_img.load()

for x in range(width):
    for y in range(height):
        p = pix[x, y]
        hidden_pix = ((p[0] & 1) << 3) | ((p[1] & 1) << 2) | ((p[2] & 1) << 1) | p[3] & 1
        new_pix[x, y] = hidden_pix * 16
new_img.show()