stega

import matplotlib.image as mpimage
import matplotlib.pyplot as plt
import sys
from PIL import Image
import stepic

def decrypt (image):
	image = (image * 255).astype(int)[:,:,0]
	imagearray = image.flatten()
	lenth = ''
	for i in range(16):
		lenth += `imagearray[i] % 2`
	lenth = int(lenth,2)
	message = ''
	for i in range(lenth):
		message += `imagearray[i+16] % 2`
	messagechar = ''
	for i in range(len(message)/8):
		messagechar += chr(int(message[i*8:i*8+8], 2))
	print messagechar

def encrypt (image, text):
	image = (image * 255).astype(int)[:,:,0]
	imagearray = image.flatten()
	ascii = map(ord, text)
	contents = ''.join(map(lambda x: bin(x)[2:].rjust(8,'0'), ascii))
	bits = len(text)*8
	howmany = bin(bits)[2:].rjust(16,'0')
	sum = howmany+contents
	mask = 0xFE
	for i in range(len(sum)):
		b = int(sum[i])
		imagearray[i] = imagearray[i] & mask | b # x and 0 = 0; 0 or x = x
	mpimage.imsave('bwresult.png', imagearray.reshape(image.shape), vmin=0, vmax=255, cmap='gray')

def blackwhite(info):
	if (info == 'z'):
		image = mpimage.imread('bw.png')
		text = open('message.txt').read()
		encrypt(image, text)
	else:
		image = mpimage.imread('bwresult.png')
		decrypt(image)

def color(info):
	if (info == 'z'):
		text = open('message.txt').read()
		image=Image.open('color.png')
		encryptcolor(image, text)
	else:
		image=Image.open('colorresult.png')
		decryptcolor(image)

def decryptcolor(image):
	d = stepic.decode(image)
	data = d.decode()
	print data

def encryptcolor(image, text):
	imagecode=stepic.encode(image,text)
	imagecode.save('colorresult.png','PNG')

u = 'n'
while (u == 'n'):
	k = raw_input('Chcesz zakodowac w pliku kolorowym, czy czarno-bialym? (k/s)\n')
	if (k == 'k'):
		w = raw_input('\nChcesz zakodowac wiadomosc z pliku message.txt czy odkodowac obraz colorresult.png? (z/o)\n')
		if (w == 'z'):
			color(w)
		else:
			color(w)
	else:
		w = raw_input('\nChcesz zakodowac wiadomosc z pliku message.txt czy odkodowac obraz bwresult.png? (z/o)\n')
		if (w == 'z'):
			blackwhite(w)
		else:
			blackwhite(w)
	u = raw_input('\nCzy chcesz zakonczyc? (t/n)\n')
	if u == 't':
		print('\nBye, bye!')