img=np.zeros((8,8),dtype=np.uint8)
print("img\n",img)
cv2.imshow("one",img)
print("读取像素点img[0,3]=",img[0,3])
img[0,3]=255
print("读取修改后的像素点img[0,3]=",img[0,3])
cv2.imshow("two",img)
print(img)
cv2.waitKey()