text: # -*- coding: utf-8 -*-
  # 读取/显示/保存图片
  import cv2
  # 图片读取
  i=cv2.imread("./lena.jpg", cv2.IMREAD_UNCHANGED)
  print("the img array is :\n", i)
  print(10*"##")
  
  # 图片显示
  print("the arr shape is:\n", i.shape)
  cv2.imshow("Demo",i)
  rtval = cv2.waitKey(0)
  print(10*"##")
  print("input key acaii no is %d"%rtval)
  cv2.destroyAllWindows()
  
  # 图像特定像素点值改变
  pix_v_before = i.item((100,100,0))
  print("(100,100) value before: \n", pix_v_before)
  print(10*"##")
  i.itemset((100,100,0),255)
  print("(100,100) value after: \n", i.item((100,100,0)))
  
  # 新图像保存
  cv2.imwrite("./lesson1.jpg",i, [int( cv2.IMWRITE_JPEG_QUALITY), 95])
  