Sobel.py

import numpy as np
import cv2
from matplotlib import pyplot as plt
img = cv2.imread("imgs/chapter5/a.jpg", 0)

dx = cv2.Sobel(img,cv2.CV_8UC1,1,0,ksize=5) # first order derivative around x
dy = cv2.Sobel(img,cv2.CV_8UC1,0,1,ksize=5) # first order derivative around y
dx2 = cv2.Sobel(img,cv2.CV_8UC1,2,0,ksize=5) # second order derivative around x
dy2 = cv2.Sobel(img,cv2.CV_8UC1,0,2,ksize=5) # second order derivative around y
dxy = cv2.Sobel(img,cv2.CV_8UC1,1,1,ksize=5) # first order derivative around x then y


f = plt.figure(figsize=(15,25))
f.add_subplot(3, 2, 1).set_title('Original Image');
plt.imshow(img, cmap="gray")
f.add_subplot(3, 2, 2).set_title('1st filter in X direction Image');
plt.imshow(dx, cmap="gray");
f.add_subplot(3, 2, 3).set_title('1st filter in Y direction Image');
plt.imshow(dy, cmap="gray");
f.add_subplot(3, 2, 4).set_title('2nd filter in X direction Image');
plt.imshow(dx2, cmap="gray");
f.add_subplot(3, 2, 5).set_title('2nd filter in Y direction Image');
plt.imshow(dy2, cmap="gray");
f.add_subplot(3, 2, 6).set_title('dxy');
plt.imshow(dxy, cmap="gray");
plt.show();