Fig. 1. Imaging model of pinhole camera^[23]

Fig. 2. Lens distortion

Fig. 3. Plane calibration boards. (a) Checkerboard; (b) solid circle; (c) concentric ring; (d) phase target

Fig. 4. Radial distortion of lens

Fig. 5. Partial processes of chessboard calibration method. (a) Checkerboard patterns captured by camera under different poses; (b) corners of calibration image

Fig. 6. Double parallel plane model

Fig. 7. Schematic of perspective protection of spatial circle^[31]

Fig. 8. Perspective projection transformation of spatial concentric circle^[33]. (a) Concentric circle in object plane; (b) concentric circle in imaging plane

Fig. 9. Principle diagram of line-edge segmentation^[40]. (a) Principle of segmentation; (b) result of segmentation

Fig. 10. Iterative calibration process of circular feature points on target^[46]

Fig. 11. Phase target patterns. (a) Horizontal sinusoidal fringe; (b) vertical sinusoidal fringe; (c) phase target determined by horizontal and vertical sinusoidal fringes

Fig. 12. Mapping relationship between world coordinates of phase points and camera pixel coordinates^[55]

Fig. 13. New applications of camera technology. (a) Optical system and opto-mechanical image of spatial fisheye camera^[94]; (b) 3D shape measurement of specular objects based on bi-telecentric lens camera^[95]; (c) application and calibration of underwater camera^[96]; (d) application and calibration of defocus camera^[97]

Fig. 14. Checkerboard images before and after calibration ^[103]. (a) Distorted; (b) corrected

Fig. 15. Self-calibration method in Ref. [104]

Fig. 16. Calibration of wide-angle lens distortion^[103]. (a) Diagram of experimental apparatus; (b) radial distorted phase distribution

Fig. 17. Schematic of bi-telecentric camera system^[106]

Fig. 18. Calibration process of defocus camera^[117]

Fig. 19. Estimation procedures of defocus map^[97]

Fig. 20. Calibration process of camera^[116]

Table 1. Performance comparison among different calibration methods