A Rotation Based Sorting Method for the Feature Points Abstracted from Skew Calibration Image

Abstract

During camera calibration, the calibration pattern image is always skew. This brings much difficult to feature points sorting, which affects calibration accuracy. In this study, a rotation based sorting method is proposed. First, detect the skew angle accurately; then, transform the original coordinates to the rotated coordinates and establish the mapping relation; then, sort the rotated coordinates; finally, sort the original coordinates using the mapping relation. To verify the feasibility of this method, an experiment is carried out. The result shows that the rotation based sorting method can sort the feature points accurately at different skew angles. Its accuracy makes this method suitable for high accurate camera calibration.