On the sensitivity of camera calibration

摘要

The orientation position errors of an object's coordinate frame are determined when the offset of image centre and lens distortion are not included in the calibration process. The orientation and position errors are [(u0)2 + (v0)2]0.5/f and [(u20+v20)T2z + (u20T2z + v20Ty2)]0.5/f, respectively, where f is the focal length, (u0, v0) is the offset of image centre and (TxTyTz) is the position of an object. We also obtain the following conclusions: (a) The offset of image centre has little effect on the determinations of the position and orientation of a coordinate frame; (b) the lens distortion will not dramatically change the position and orientation of a coordinate frame; (c) the scale factor has a great effect on the position of a coordinate frame, and on the accuracy of measurement; (d) the offset of image centre is more sensitive than the lens distortion on the determinations of the position and orientation of a coordinate frame. Finally, some experimental results are given to demonstrate the theoretical analysis given in this paper.