Image Processing using python. [How to undo a for loop]

[Biyiha Tobie]

Good morning guys, 

I am working on an image processing project using python.

I had to divide an image(256x256) into 8by8 blocks and I achieved this. But after processing, I have to undo this process. Please, can someone give me a hand?. This is the for loop to divide the image to 8by8 below. Thanks for the help in advanced.

img = np.array(image)

windowsize_r = 8

windowsize_c = 8

l = len(img)

f = np.array([])

for r in range(0, l, windowsize_r):

    for c in range(0, l, windowsize_c):

        windows = img[r:r+windowsize_r,c:c+windowsize_c]

        wd1 = np.zeros((64,1))

        wd1 = windows.ravel()

        wd1 = wd1.reshape(64,1)

        f = np.append(f,wd1)

        

x = f.reshape(1024,64)