stegchris2.py

from PIL import Image
import time, argparse

parser = argparse.ArgumentParser()
parser.add_argument("-m", help="message to encode")
parser.add_argument("-f", help="image path")
args = parser.parse_args()

if args.f is None:
    exit("Need to specify image path!")

im = Image.open(args.f, 'r')
width,height = im.size

def encode_message(msg = "Hello World!"):

    i = 0
    for x in range(0,width):
        for y in range(0,height):

            r,g,b,a = im.getpixel((x,y))

            if a <= 25 and i < len(msg):

                im.putpixel((x,y),(ord(msg[i]),g,b,a))

                i += 1

            elif i >= len(msg):

                im.putpixel((x,y),(69,69,69,69))
                return

def decode_message():

    msg = ""

    for x in range(0,width):
        for y in range(0,height):

            r,g,b,a = im.getpixel((x,y))

            if a <= 25:
                msg += chr(r)
            elif (r,g,b,a) == (69,69,69,69):
                return msg

    
    return msg

if (args.m is not None):
    msg = open(args.m,'rb').read()
    encode_message(msg)
    im.save(args.f)
else:
    print decode_message()