Image pickup system employing a three-dimensional reference object

Abstract

The present invention provides a three-dimensional chart, a parameter acquiring method and an information processing device that are used for carrying out camera calibration in a wide range with high precision. For this reason, a plurality of unit graphic forms the sizes of which are coded by using different cross-ratios are placed on side faces of a three-dimensional chart. The cross-ratios of unit graphic forms are calculated from a picked-up image of the three-dimensional chart, and by collating these with actual values, the position and orientation of the image-pickup point are determined. The shifting average of the heights of the unit graphic forms is made approximately proportional to the distance from the apex so that it is possible to reduce the limitation of image-pickup distances. A movable camera is attached to a subject-use camera, and upon picking up an image of the subject, an image of the three-dimensional chart is also picked up simultaneously. Based upon the position and orientation of the movable camera found out by the above-mentioned sequence of image-pickup processes and the relative position and orientation between the two cameras that have been preliminarily found, it is possible to determine the position and orientation of the subject-use camera.