Real-time extraction of light stripe central line based on contour polygonal representation

A method to extract a light stripe central line with sub-pixel precision in real time was presented.First,the light stripe was segmented by light stripe contour tracking and the contour polygon representation.Then,based on the counter-clockwise sorting characteristics of contour and the orthogonal relationship between cross section direction and corresponding segmented light stripe direction,the scanning line direction of segmented light stripe was calculated by using a serial representation method.Finally,an adaptive barycenter method that can change adaptively the cross section width was designed on the scanning line to calculate the center sub-pixel coordinates.For the 640 pixel×480 pixel light stripe bitmaps captured by a 3D laser foot scanner with 6 CCDs at typical positions,the extraction time for central line is less than 3.1 ms in sub-pixel precision.The algorithm proposed here can satisfy the requirements of multi-sensor line laser scanning vision measurement system for real time,high precision as well as high speeds.