glitch_image.py

import cv2
import numpy as np
from random import randint, random

intensity = 10
glitch_row_size = 20

img = cv2.imread('/tmp/screenshot.png')
org_rows, org_cols, cnls = img.shape

img = cv2.resize(img, (0,0), fx=0.3, fy=0.3)
 
rows, cols, cnls = img.shape

b, g, r = cv2.split(img)
channels = []
fixed_channel = False

for c in (b, g, r):
    if (random() > 0.4) and not fixed_channel:
        M = np.float32([[1, random() /100, randint(intensity * -1, intensity)],[random()/100, 1, randint(intensity * -1, intensity)]])
        c = cv2.warpAffine(c,M,(cols,rows))
        fixed_channel = True

    for i in range(0,5):
        begin = randint(0, rows)
        if (begin > rows - glitch_row_size):
            end = randint(begin, rows)
        else:
            end = begin + randint(0, glitch_row_size)
           
        area = c[begin:end, :]
        offset = randint(begin*-1, rows-end)
        area = np.resize(area, (end-begin, cols-abs(offset)))
        print(offset, cols)
        c[(begin+offset):(end+offset), abs(offset):cols] = area
 
    channels.append(c)

channels = tuple(channels)

img = cv2.merge(channels)
img = cv2.resize(img, (org_cols, org_rows), interpolation= cv2.INTER_NEAREST)

cv2.imwrite('/tmp/screen_locked.png', img)