Research on corner detection algorithm based on the long depth of field binocular camera with wavefront coding

The long depth of field camera with wavefront coding is introduced in Design of Long Depth of Field Array Optical Components Defect Detection System [1]. It can obtain the whole object information at one time within 3-13 m of the depth of field. However, when binocular calibration is used in corner detection, the scalability and asymmetry of the point spread function will lead to images missing and redundancy. This article describes an improvement in the Hessian corner detector to solve this problem. Firstly, the local negative maximum with the largest change in curvature is extracted around the X corner, and the initial corner set is obtained according to their central symmetry. Then, by making use of the distance characteristics between corners of the checkerboard and constraining the angle characteristics of these corners, the false corners are filtered and the correct corner set is obtained. Finally, the corners set is sorted and the starting direction of the sorting is constrained. The corners extracted through this algorithm can be better applied to camera calibration and positioning. Experiments show that the proposed detector is better than OpenCV detector in the accuracy of positioning, calibration and measurement, and has certain robustness.