An algorithm for subpixel edge location of circular features based on Zernike moments and moment-preserving
Qingbin Tong, Xiaodong Zhang, Zhenliang Ding, Feng Yuan · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2010
In order to satisfy the stringent requirements for the high accurate detection of circular feature in such applications as the vision measurement of electronic components and camera calibration, based on the principle of orthogonal Zernike moments and simple moment-preserving transform, a subpiexl edge detection algorithm for the curve of circular feasures is proposed. A circular-arc geometry is assumed for the boundary inside the detection area of template. The new arc-edge detector is designed as a cascade process using Zernike linear-edge detector and simple moment-preserving transform and a look-up table. The validity and detecting precision for the algorithm are studied. The experimental results show that the algorithm is very accurate and stable, and the measuring accuracy is better than 0.03 pixel. The proposed method is very effective in detecting circular features and as well ellipse curve for vision measurements.