import cv2
import numpy as np
path = 'C:/Users/79216/Downloads/laba3.jpg'
grey = 'C:/Users/79216/Downloads/laba3./GRAYSCALE.jpg'
img = cv2.imread(path)
img_inv = cv2.imread(path, cv2.IMREAD_GRAYSCALE)
cv2.imshow('RGB', img)
cv2.imshow('GRAYSCALE', img_inv)
cv2.imwrite(grey, img_inv)
for i in range(img_inv.shape[0]):
    for j in range(img_inv.shape[1]):
        img_inv[i][j] = 255 - img_inv[i][j]
cv2.imshow('img_inv', img_inv)
for i in range(img.shape[0]):
    for j in range(img.shape[1]):
        [b,g,r] = img[i][j]
        img[i][j] = [b, r, g]
cv2.imshow('BRG', img)
cv2.waitKey(0)