Learning OpenCV 4 Computer Vision with Python 3 - Third Edition

Detecting lines

First of all, let's detect some lines. We can do this with either the HoughLines function or the HoughLinesP function. The former uses the standard Hough transform, while the latter uses the probabilistic Hough transform (hence the P in the name). The probabilistic version is so-called because it only analyzes a subset of the image's points and estimates the probability that these points all belong to the same line. This implementation is an optimized version of the standard Hough transform; it is less computationally intensive and executes faster. HoughLinesP is implemented so that it returns the two endpoints of each detected line segment, whereas HoughLines is implemented so that it returns a representation of each line ...