Sensitivity analysis of line correspondence

This correspondence shows that line and point correspondences can obtain orientation with the same accuracy, and that when using line correspondence, using more matching lines does not guarantee that the orientation error can be reduced. Orientation detection using line correspondence is very sensitive to errors in image location. We provide a sensitivity analysis of line correspondence, and conditions which lead to orientation sensitivity due to errors in image location. The orientation error using line correspondence due to offset from the image center is obtained analytically. A method for selecting three matching lines, such that orientation is not sensitive to image location errors and using more matching edges to improve the accuracy of orientation is given. Finally three examples are given to illustrate the concepts and support the theoretical results. The first example shows that an orientation with reasonable accuracy may be obtained by using three matching lines. The second example demonstrates that both point and line correspondences can obtain orientation with the same accuracy. The last example supports experimentally the result regarding the orientation error using line correspondence due to offset of the image center and lens distortion