LSB Algorithm

import os, sys
import Image
import binascii
import optparse

#hide
def hide(image, message):
    msg = Image.open(message)
    msg = msg.convert("RGBA")
    data = msg.getdata()

    img = Image.open(image)
    img = img.convert("RGB")
    data2 = img.getdata()
    newData = []
    index = 0

    for item in data:
        if item[0] == 0:
            if (data2[index][0])%2 == 0:
                newData.append((data2[index][0] + 1, data2[index][1], data2[index][2]))
            else:
                newData.append((data2[index][0],data2[index][1], data2[index][2]))
            index = index + 1
        else:
            if (data2[index][0])%2 == 1:
                newData.append((data2[index][0] - 1,data2[index][1], data2[index][2]))
            else:
                newData.append((data2[index][0],data2[index][1], data2[index][2]))
            index = index + 1

    img.putdata(newData)
    img.save("new_"+image, "PNG")

    return "Completed!"

#extract
def extract(image):
    img = Image.open(image)
    img = img.convert("RGB")
    data = img.getdata()
    orgData = []

    for item in data:
        if item[0]%2 == 0:
            orgData.append((255,255,255))
        else:
            orgData.append((0,0,0))

    img.putdata(orgData)
    img.save("msg_"+image, "PNG")

    return "Completed!"

def Main():
        parser = optparse.OptionParser('usage %prog '+\
        '-H/-E <target file>')
    parser.add_option('-H', dest='hide', type='string', \
        help='target picture path to hide another image')
    parser.add_option('-E', dest='extract', type='string', \
        help='target picture path to extract the secret image')

    (options, args) = parser.parse_args()
    if (options.hide != None):
        mesg = raw_input("Enter a message to hide: ")
        print hide(options.hide, mesg)
    elif (options.extract != None):
                print extract(options.extract)
    else:
        print parser.usage
        exit(0)


if __name__ == '__main__':
    Main()