use this code for canny edge detection

cannyed.py

# %matplotlib inline 
import numpy as np

import cv2 as cv
from matplotlib import pyplot as plt
img = cv.imread('Sample/Sample.tif')
edges = cv.Canny(img,100,200)
plt.figure(figsize=(30, 25))
# plt.subplot(121),plt.imshow(img,cmap = 'gray')
# plt.title('Original Image'), plt.xticks([]), plt.yticks([])
# plt.subplot(122),plt.imshow(edges,cmap = 'gray')
# plt.title('Edge Image'), plt.xticks([]), plt.yticks([])
# plt.savefig('Sample/OriginalvsCannyED.jpg')
plt.imshow(edges, cmap='gray')
plt.savefig('Sample/cannyED.jpg')