en_de_stenograf.py

import Image

def getBit(num, pos):
    return (num & (1 << pos)) >> pos

def numToBit(inN):
    out = []
    for i in xrange(8):
        out.append(getBit(inN,i))
    return out

def bitToNum(in_array):
    out =0
    for i in xrange(len(in_array)):
        if in_array[i]:
            out+=pow(2,i)
    return out

def loadImg(file_name):
    out = Image.open(file_name).convert('RGB')
    pixels = out.load()
    return out, pixels, out.size

def writeChar(pixs, cursor, char):
    char = numToBit(ord(char))
    r = numToBit(pixs[cursor[0],cursor[1]][0])
    g = numToBit(pixs[cursor[0],cursor[1]][1])
    b = numToBit(pixs[cursor[0],cursor[1]][2])

    r[0] = char[0]
    r[1] = char[1]

    g[0] = char[2]
    g[1] = char[3]
    g[2] = char[4]

    b[0] = char[5]
    b[1] = char[6]
    b[2] = char[7]

    r = bitToNum(r)
    g = bitToNum(g)
    b = bitToNum(b)

    updatedPix = (r, g, b)
    pixs[cursor[0],cursor[1]] = (r, g, b)


def readChar(pixs, cursor):
    char_array = []
    r = numToBit(pixs[cursor[0],cursor[1]][0])
    g = numToBit(pixs[cursor[0],cursor[1]][1])
    b = numToBit(pixs[cursor[0],cursor[1]][2])

    char_array.append(r[0])
    char_array.append(r[1])
    char_array.append(g[0])
    char_array.append(g[1])
    char_array.append(g[2])
    char_array.append(b[0])
    char_array.append(b[1])
    char_array.append(b[2])

    return chr(bitToNum(char_array))

def isEncript(pixs):
    if readChar(pixs, (0,0)) == '/':
        return 1
    else:
        return 0

def encode(in_image, in_text):
    img, pixels, size = loadImg(in_image)
    len_text = len(in_text)

    if isEncript(pixels):
        return 1

    if len_text > (size[0]*size[1]-3):
        return 2

    writeChar(pixels, (0,0), '/')
    
    for i in xrange(3):
        writeChar(pixels, (0,i+1), chr(len_text))
    k=0
    for i in range(3,size[1]-3):
        for j in range(size[0]):
            if k < len_text:
                print in_text[k]
                writeChar(pixels, (j,i), in_text[k])
            k+=1
    return img

def decode(in_image):
    pixs = in_image.load()
    size = in_image.size
    if (not isEncript(pixs)):
        return 'Error'
    out=''
    max_len=ord(readChar(pixs, (0,1)))
    for i in range(3,size[1]-3):
        for j in range(size[0]):
            if len(out) >= max_len:
                break
            out+=readChar(pixs, (j,i))
    return out

img = encode('in.png', 'Aeyzrfr gsdfgsd dgs ///')
img.show()
print decode(img)
img.save('out.png')
'''            
print numToBit(40)
print bitToNum(numToBit(40))'''