Fig. 1. Checkerboard projection imaging model

Fig. 2. Checkerboard on imaging plane

Fig. 3. Hough transform schematic

Fig. 4. Results of checkerboard straight line separation under Hough transform. (a) Original image; (b) image after straight line separation

Fig. 5. Discrimination of the USAN area of the circular template. (a) Circular template near the corner point; (b) distribution of the USAN area corresponding to the template

Fig. 6. Mathematical model of the circular template USAN region

Fig. 7. Corner precise positioning. (a) Template kernel coordinate extraction; (b) corner search area; (c) minimization criterion positioning

Fig. 8. Experimental site and equipment

Fig. 9. Corner detection results of the method in this paper

Fig. 10. Scattered point distributions of reprojection error. (a) Method of this paper; (b) method of Ref. [10]; (c) method of Ref. [16]; (d) method of Ref. [17]

Fig. 11. Results of checkerboard corner detection under different lighting conditions. (a) Dimmed light (g=25.9); (b) medium light (g=76.5); (c) bright light (g=165.8)