The nonmetric estimation of center of distortion based on concentric circles pattern

In the distortion correction of camera lens, the methods employed to estimate the center of distortion are either complicated or requiring device to measure coordinates with high precision. By analyzing the geometric characters of circles with radial distortion, we find that the center of distortion must lies on the line which goes through every center of the distorted concentric circles. In this way, a method using concentric circles to estimate the center of distortion is proposed. Our method is entirely noniterative and nonmetric, and has no any constraint on the radius or the location of the concentric circles. As for any in-plan pattern in the world coordinate, we provide a general way to simulate its corresponding image with distortion. The simulation experiments show the error of the proposed method is less than 0.5 pixels and behaves very well in noisy images. We also point out an effective approach to reduce error.