关键词: 二次曲线, 摄像机标定, 圆环点, 共面圆, 射影不变量

Abstract: In view of camera calibration’s preferable robustness based on conic，a new method for camera calibration based on coplanar circles is proposed.The technique only requires three coplanar circles（or more） which are arbitrarily distributed.There is no demand of orientation of conics，the matching between model plane and image，and solution of non-linear system of equations.In the paper algorithm is described in view of geometry，and it’s validity is proved in view of algebra.Experiment results have shown that the method proposed is not only accurate and robust，but also has the better practicality because the method proposed is not image matching and information about geometric information of conic such as size and position.

Key words: conic, camera calibration, circular points, coplanar circles, projective invariant