Patent ID: 7821535

Claim:
An information processing method, comprising: an acquisition step of acquiring an image obtained by capturing an index arranged in a physical space using a camera; a first calculation step of calculating a coordinate position (x o , y o ), in the image, of the index captured in the image; a second calculation step of calculating a projection position (x p , y p ) obtained by projecting an index arranged in the physical space onto the image, by using a camera parameter, wherein the camera parameter includes k c being a cubic parameter of a radial distortion, k q being a quintic parameter of the radial distortion, k v2h being a parameter indicating aspect ratio, (c x , c y ) being parameters indicating a distortion central position, (f x , f y ) being a focal length, and (p x , p y ) being a principal point position, and the k q is fixed to zero; a first correction step of correcting, according to the Newton method, the camera parameter in which the k q is fixed to zero, by using a difference between the projection position (x p , y p ) calculated in the second calculation step and the coordinate position (x o , y o ) calculated in the first calculation step; a third calculation step of calculating a projection position (x p , y p ) obtained by projecting an index arranged in the physical space onto the image, by using the camera parameter corrected in the first correction step; a second correction step of correcting, according to the Newton method, the k q included in the camera parameter corrected in the first correction step, by using a difference between the projection position (x p , y p ) calculated in the third calculation step and the coordinate position (x o , y o ) calculated in the first calculation step; a fourth calculation step of calculating a projection position (x p , y p ) obtained by projecting an index arranged in the physical space onto the image, by using the camera parameter corrected in the second correction step; and a third correction step of correcting, according to the Newton method, the camera parameter which is corrected in the second correction step and in which the k q and k v2h are fixed, by using a difference between the projection position (x p , y p ) calculated in the fourth calculation step and the coordinate position (x o , y o ) calculated in the first calculation step.