Patent ID: 6594600
Filing Date: 2003-07-15
Classification: G01B,G01C,G06T

Abstract:
A method of calibrating the original position and orientation of a camera disposed on a mobile support in an environment, comprising:providing the environment with a test object at a known position and orientation; taking an image of the test object with the camera; analyzing the image of the test object with a processing system by reading positions of tracks (Pp) of characteristic marks of the test object on the image and deducing directions and distances between the characteristic marks and the camera, and then a position and an orientation of the camera with respect to the test object; and deducing the directions and distances between the characteristic marks and the calibration camera by carrying out a retro-projection of the centers of the tracks of the characteristic marks of the test object first on to a plane (II) passing through the origin of the test object reference frame and parallel to the plane of the image along lines converging towards a single focus (F), then in space, perpendicular to the said parallel plane in order to obtain retro-projection points (Â° P) on to the plane of the image along lines converging towards the focus (F) in order to obtain projection points (Â° Pp) , and a positional correction of the retro-projection points in order to minimize an error estimation criterion between coordinates of the centers of the tracks (Pp) of the characteristic marks and the projection points (Â° pp).