opencv（Python/c++）:canny边缘检测

python版

import cv2
import numpy
img=cv2.imread('dog.jpeg',0)
cv2.imwrite('canny.jpeg',cv2.Canny(img,200,300))
cv2.imshow('canny',cv2.imread('canny.jpeg'))
cv2.waitKey()
cv2.destroyAllWindows()

c++版