Is there any edge detection in opencv(python) with white background?

Question

OpenCV中是否有像canny这样的边缘检测滤镜，但我希望背景为白色，边缘为黑色

Answer 1

I don't think there is such concept but you can achieve this way

import cv2
import numpy as np
img = cv2.imread("arch.jpg")
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

edges = cv2.Canny(gray,100,200)
ret,th2 = cv2.threshold(edges,100,255,cv2.THRESH_BINARY_INV)


cv2.imshow("img",th2)
cv2.waitKey(0)
cv2.destroyAllWindows()