text: # coding: utf-8
  from cv2 import cv2
  import numpy as np
  
  img = cv2.imread(r'pictures\a.jpg')
  
  pixel = img[200, 200]
  img[200, 200] = [255, 255, 255]
  b = img[200, 200, 0]
  g = img[200, 200, 1]
  r = img[200, 200, 2]
  print(r)
  r = img[200, 200, 2] = 1
  print(r)
  print(img[200,200])
  cv2.namedWindow("img", 0)
  cv2.imshow('img', img)
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  