## Purdue CS 177 Image Manipulation Project
## Written by Samantha Feulner, Created 7/15/2012
## Last Modified 7/25/2012

from PIL import Image

 ##Open and display images A, B, and C
def openFirst(A):
    im1 = Image.open(A)
    im1.show()
    return im1

def openAll(A, B, C):

    im1 = Image.open(A)
    im2 = Image.open(B)
    im3 = Image.open(C)
    im1.show()
    im2.show()
    im3.show()

 ##Create a black and white copy of an image and display with the original
def blackAndWhite (image):

    ##Open the image
    X0 = Image.open(image)
    ##Remember to convert the image to RGB when editing the pixels
    X0 = X0.convert('RGB')
    width, height = X0.size
    X0.show()

    for x in range(height):    ##Nested for loop iterates through all the pixels
        for y in range(width):
            r, g, b = X0.getpixel((y, x))
            brightness = int(round(0.33*r + 0.33*g + 0.33*b)  )
            X0.putpixel((y, x), (brightness, brightness, brightness))

    ## Save the modified image
    newPre = image[:-4]
    cfileName = newPre+'_BW_mod.gif'
    X0.save(cfileName)
    X0.show()


##Removes green from every pixel in the image    
def noGreen(image): 

    X0 = Image.open(image)
    X0 = X0.convert('RGB')
    width, height = X0.size
    X0.show()

    for x in range(height):
        for y in range(width):
            r, g, b = X0.getpixel((y, x))
            X0.putpixel((y, x), (r, 0, b))

    newPre = image[:-4]
    cfileName = newPre+'_NoGreen_mod.gif'
    X0.save(cfileName)
    X0.show()
    
##The lowest four bits of each color component in the pixels are set to zero
def zeroLowBits (image): 

    X0 = Image.open(image)
    X0 = X0.convert('RGB')
    width, height = X0.size
    X0.show()
    X1 = X0.copy()
    for x in range(height): 
        for y in range(width):
            r, g, b = X0.getpixel((y, x))

            r = r & int('11110000',2)
            g = g & int('11110000',2)
            b = b & int('11110000',2)

            X1.putpixel((y, x), (r, g, b))
        
    newPre = image[:-4]
    cfileName = newPre+'_Zero4LowBits_mod.gif'
    X1.save(cfileName)
    X1.show()

##The bits of each color component in the pixels are shifted by k bits to the right 
def shiftBitsLeft (image, shift):
    X0 = Image.open(image)
    X0 = X0.convert('RGB')
    X0.show()
    X1 = X0.copy()
    width, height = X0.size
    for x in range(height): 
        for y in range(width):
            r, g, b = X0.getpixel((y, x))
            r = (r << shift) & 255
            g = (g << shift) & 255
            b = (b << shift) & 255
            X1.putpixel((y, x), (r, g , b))
    X1.show()
    newPre = image[:-4]
    cfileName = newPre+'_ShiftLeft'+str(shift)+'_mod.gif'
    X1.save(cfileName)


##The bits of each color component in the pixels are shifted by k bits to the right 
def shiftBitsRight (image, shift):
    X0 = Image.open(image)
    X0 = X0.convert('RGB')
    X0.show()
    X1 = X0.copy()
    width, height = X0.size
    for x in range(height): 
        for y in range(width):
            r, g, b = X0.getpixel((y, x))
            r = r >> shift
            g = g >> shift
            b = b >> shift
            X1.putpixel((y, x), (r, g , b))
    X1.show()
    newPre = image[:-4]
    cfileName = newPre+'_ShiftRight'+str(shift)+'_mod.gif'
    X1.save(cfileName)

# check hiding op
def chk1(pa,ps,pa1,ps1,co):
    if pa>=256 or pa<0: 1/0
    if ps>=256 or ps<0: 2/0
    if co>=256 or co<0: 3/0
    if pa1 != 0:
        if pa1<16: 4/0
    if ps1>=16 or ps1<0: 5/0
    sh = ps - (ps1<<4)
    if sh > 16 or sh<0: 6/0

##Hides picture S in picture A by placing the four higher bits of S as the four lower bits of A   
def hidePicture(A, S):

    antique0 = Image.open(A)
    antique0 = antique0.convert('RGB')
    awidth, aheight = antique0.size
    antique0.show()

    smuggle0 = Image.open(S)
    smuggle0 = smuggle0.convert('RGB')
    swidth, sheight = smuggle0.size
    smuggle0.show()

    combine = Image.new('RGB',(awidth,aheight))

    if awidth !=swidth:
        print("Images must be equal in size")
    elif aheight != sheight:
        print("Images must be equal in size")
    else:
        for x in range(aheight): 
            for y in range(awidth):
                rs, gs, bs = smuggle0.getpixel((y, x))
                if (rs & 0xFF) != rs: 1/0
                ra, ga, ba = antique0.getpixel((y, x))
                if (ra == rs) and (ga==gs) and (ba==bs):
                    print('.',sep='',end='')
                # shift high bits of smuggled to low bits
                rs = rs >> 4
                gs = gs >> 4
                bs = bs >> 4
                ra = ra & 0xF0
                ga = gs & 0xF0
                ba = ba & 0xF0
                ra1 = ra+rs
                ga1 = ga+gs
                ba1 = ba+bs
##                if ((ra1 & 0xF0)>>4) == rs1:
##                    print('.',sep='',end='')

                combine.putpixel((y, x),(ra1, ga1, ba1))

        newPre = A[:-4]
        cfileName = newPre+'_pregnant_mod.gif'
        combine.save(cfileName)
        combine.show()

##extract image of low-order 4 bits by left shift of 4 
def extractPicture (image):
    shift = 4
    X0 = Image.open(image)
    X0 = X0.convert('RGB')
    X0.show()
    width, height = X0.size
    print("w",width,"h",height)
    X1 = Image.new('RGB',(width,height))
    X1.show()
    for x in range(height): 
        for y in range(width):
            r, g, b = X0.getpixel((y, x))
            r1=r&15
            g1=g&15
            b1=b&15
            r2 = (r1 << shift) & 255
            g2 = (g1 << shift) & 255
            b2 = (b1 << shift) & 255
            X1.putpixel((y, x), (r2, g2 , b2))
            if (r&0x0F)==((r&0xF0)>>4): print('.')
    X1.show()
    newPre = image[:-4]
    cfileName = newPre+'_extracted_mod.gif'
    X1.save(cfileName)

##Morphs two images using the Image.blend function and displays the morphing steps in a loop
def morphPicture (image1, image2):
    X1 = Image.open(image1)
    X2 = Image.open(image2)

    x1width, x1height = X1.size
    x2width, x2height = X2.size

    if x1width != x2width:
        print("Images must be equal in size")
    elif x1height != x2height:
        print("Images must be equal in size")
    else:
        for x in range (0, 17, 1):
            combine = Image.blend(X1, X2, x/16)
            combine.show()

def control():
    print("Operations:")
    print("  0 - exit")
    print("  1 - zero 4 low-order bits")
    print("  2 - shift left")
    print("  3 - shift right")
    print("  4 - hide picture")
    print("  5 - extract picture")
    print("  6 - zero lower 4")
    code = eval(input("choice: "))
    if code == 0: return code, 0
    else:
        src = input("file name: ")
    return code, src

def zeroLow4(fname):
    X0 = Image.open(fname)
    X0 = X0.convert('RGB')
    X0.show()
    width, height = X0.size
    for x in range(height): 
        for y in range(width):
            r, g, b = X0.getpixel((y, x))
            r = r >> 4
            g = g >> 4
            b = b >> 4
            X0.putpixel((y, x), (r, g , b))
    X0.show()
    for x in range(height): 
        for y in range(width):
            r, g, b = X0.getpixel((y, x))
            r = r << 4
            g = g << 4
            b = b << 4
            X0.putpixel((y, x), (r, g , b))
    X0.show()
    newPre = fname[:-4]
    cfileName = newPre+'_ZeroLow'+'_mod.gif'
    X0.save(cfileName)
    
def main():
    todo, fname = control()
    while todo != 0:
        if todo == 1: zeroLowBits(fname)
        elif todo == 2:
            k = eval(input('enter shift: '))
            shiftBitsLeft(fname,k)
        elif todo == 3:
            k = eval(input('enter shift: '))
            shiftBitsRight(fname,k)
        elif todo == 4:
            fname2 = input('hidden file name: ')
            hidePicture(fname, fname2)
        elif todo == 5:
            extractPicture(fname)
        elif todo == 6:
            zeroLowBits(fname)
        else:
            print("unknown choice")
        todo, fname = control()

##    openAll("X1.gif", "X2.gif", "X3.gif")
##    blackAndWhite("X2.gif")
##    noGreen("GreenFish.gif")
##    zeroLowBits("X1.gif")
##    shiftHighBits("X3.gif", 5)
##    hidePicture("X1.gif", "X2.gif")
##    morphPicture("X1.gif", "X2.gif")
    

main()