Image gradient : Sobel, Scharr and Laplacian.

import cv2
import numpy as ns

img=cv2.imread('SampleImage.jpg',0)    # Loading image in Gray scale
sobel=cv2.Sobel(img,cv2.CV_64F,0,1,(5,5),ksize=5)
sarcher=cv2.Sobel(img,cv2.CV_64F,1,0,(5,5),ksize=5)
laplecian=cv2.Laplacian(img,cv2.CV_64F,ksize=5)

while True:
    cv2.imshow("img",img)
    cv2.imshow("sobel",sobel )
    cv2.imshow("sarcher",sarcher )
    cv2.imshow("laplecian",laplecian )

    if cv2.waitKey(0) & 0xFF == 27:
        break
cv2.destroyAllWindows()