Fig. 1. Schematic of the measuring system

Fig. 2. Images of hollow ring marker matrix captured by the camera. (a) Texture image; (b) red dots representing the center of each hollow ring marker

Fig. 3. Fringe patterns displayed on the screen. (a) Horizontal fringe; (b) vertical fringe

Fig. 4. Feature points matching using absolute phase image

Fig. 5. Calibration of parameters d1 and d2

Fig. 6. Experimental system

Fig. 7. Reprojection error of the calibrated camera (pixel)

Fig. 8. Error of the calibrated extrinsic parameters

Fig. 9. Photos of (a) concave mirror and (b) manufactured artificial step

Fig. 10. Measured 3D shapes. (a) Concave mirror; (b) artificial specular step