Translator Disclaimer
15 October 2012 Center location of circular targets with surface fitting method
Author Affiliations +
Circular target is one of the most commonly used artificial markers in machine vision. An alternative method for center location of circular targets with sub-pixel accuracy based on surface fitting is presented in this paper. The gray level distribution around the image of the circular target is modeled starting form one-dimensional step edge smoothed with Gaussian filter, and then extending to two-dimensional case by means of variable substitution of the elliptical rotation. The surface model aforementioned is a non-elementary function, so an approximate expression is found subsequently to make the numerical computation executable. The parameters of the surface model are estimated with algebraic least square fitting, from which the accurate center location can be calculated. The experiment results show the proposed method is more robust to image degradation comparing with the most commonly used method.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yongkai Yin, Meng Wang, Xiaoli Liu, and Xiang Peng "Center location of circular targets with surface fitting method", Proc. SPIE 8499, Applications of Digital Image Processing XXXV, 84991U (15 October 2012);

Back to Top