Sub-pixel edge extraction method based on subpixel edge detection model

Abstract

Image edge extraction and recognition are of great significance for the measurement accuracy of various workpieces and parts. It is important to burrs and edge shadows, as well as the effect of shooting under illumination conditions. Finally, the number of representative image edge profiles, the number and coordinates of sub-pixel points of each edge profile, and the length of the total edge profile are calculated. For sub-precision edge extraction of a given image, we first pre-process the image, roughly locate the image edges using the Canny operator, then sample the 7x7 region around the edge points, optimize the sub-pixel accuracy using the Zernike 7x7 template, and finally obtain the output point set.