OpenCV 4 with Python Blueprints - Second Edition

Detecting and emphasizing prominent edges

Again, when it comes to edge detection, the challenge often does not lie in how the underlying algorithm works, but instead lies in which particular algorithm to choose for the task at hand. You might already be familiar with a variety of edge detectors. For example, Canny edge detection (cv2.Canny) provides a relatively simple and effective method to detect edges in an image, but it is susceptible to noise.

The Sobel operator (cv2.Sobel) can reduce such artifacts, but it is not rotationally symmetric. The Scharr operator (cv2.Scharr) was targeted at correcting this but only looks at the first image derivative. If you are interested, there are even more operators for you, such as the Laplacian ridge ...