#!/usr/bin/python3
 #!--*-- coding: utf-8 --*-- 
  import cv2
  img = cv2.imread("elon.jpg")

  ## Image to Gray Image
  gray_image = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

  ## Gray Image to Inverted Gray Image
  inverted_gray_image = 255-gray_image

  ## Blurring The Inverted Gray Image
  blurred_inverted_gray_image = cv2.GaussianBlur(inverted_gray_image, (19,19),0)

  ## Inverting the blurred image
  inverted_blurred_image = 255-blurred_inverted_gray_image

  ### Preparing Photo sketching
  sketck = cv2.divide(gray_image, inverted_blurred_image,scale= 256.0)

  cv2.imshow("Original Image",img)
  cv2.imshow("Pencil Sketch", sketck)
  cv2.waitKey(0)

如图：