Research on fast extraction algorithm of cross line laser image center

Abstract

When measuring three dimensional information of workpiece and object by laser triangulation method, one of the key issues about precision detection is how to quickly and accurately extract the center coordinate position of projected laser stripe. In the detection process of medium and heavy plate flatness, we use the cross line laser as the light source, attain image information by CMOS camera and store them in the computer. With digital image processing technology, we extract the center coordinate position, and utilize space projection matrix to convert image coordinate into a three-dimensional coordinate, thus obtaining the flatness of medium and heavy plate. Therefore, it will help improve the detection accuracy of the medium and heavy plate flatness to accurately extract the center coordinate position of the cross line laser stripe. Based on the characteristic that the pixels sum in the eight neighboring field of cross line laser center are four, this paper determine the coordinate of the center. Compared with the least square method, it verifies the reliability of the algorithm presented in this paper. The results can reach sub-pixel level and the system has high speed with processing time about 0.1252 s, improved by 92.22%.