大视场多像机视频测量系统的全局标定

Abstract

An accurate global calibration method for a muti-camera videogrammetric system with large field-of-view is presented.Firstly,a cross target with feature points pasted on its two sides is designed as the calibration reference pattern,and the world coordinates of these feature points are reconstructed using the XJTUDP photogrammetric system.Then,the calibration target is placed in the public field-of-view and its images shown at different orientations are captured by the four cameras simultaneously.Finally,based on a 10-parameter nonlinear camera model,the capatured images are calibrated successively and the camera interior parameters and global orientation parameters with respect to a predefined global coordinate system are obtained.Experimental result indicates that the proposed calibration method can offer a considerable accuracy in a re-projection error less than 0.05pixel.By the proposed method,the four-camera videogrammetric system can achieve a relative accuracy of 1 / 4 000on length measurement.It can satisfy the demands of the multi-camera videogrammetric measurement with large field-of-view for precision and efficiency.