utils.py

from PIL import Image

def function(x):
    if x%2 is 0:
        return x+1
    return x-3

def function2(x):
    if x%3 is 0:
        return x-3
    return x-7

def swap(ai,aj,bi,bj, image, arr):
    # Code to swap pixel RGB values
    arr[ai,aj],arr[bi,bj]= arr[bi,bj],arr[ai,aj]

def efficiency(orig, enco, W, H):
    different = 0
    for i in range(W):
        for j in range(H):
            if orig[i,j]!=enco[i,j]:
                different = different+1
    print('Different pixels: '+ str(different))
    print('Total pixels: '+ str(W*H))
    print('Efficiency: '+ str(different*100.0/(W*H)) +" %")

def efficiency_calc(image_path,im,arr,saved_path):
    im2 = Image.open(saved_path, "r")
    (W,H) = im.size
    # To calculate efficiency of the algorithm
    arr2 = im2.load()
    efficiency(arr2, arr, W, H)
    im.show()

def cascade(xy, N, W, H):
    cas= []
    cas.append((xy[0]%W,xy[1]%H))
    i= 0
    for i in range(N):
        xy = (function(xy[0])%W,function(xy[1])%H)
        cas.append(xy)
    return cas

def color(arr,val,W,H):
    for i in range(W):
        for j in range(H):
            (r,g,b)=arr[i,j]
            arr[i,j]=((r^(val[0]%256))%256,(g^(val[1]%256))%256,(b^(val[2]%256))%256)

def automate_swap(alpha, beta, N, image, arr):
    for i in range(N):
        swap(alpha[i][0],alpha[i][1],beta[i][0],beta[i][1], image, arr)

def automate_swap_dec(alpha, beta, N, image, arr):
    for i in range(N):
        swap(alpha[N-1-i][0],alpha[N-1-i][1],beta[N-1-i][0],beta[N-1-i][1], image, arr)