Fig. 1. Schematic of three-dimensional measurement system and grating fringe patterns. (a) Three-dimensional measurement system of structured light; (b) binary grating fringe pattern; (c) binary grating fringe pattern after defocusing

Fig. 2. Plaster pictures collected by camera. (a) 1^st picture collected; (b) picture collected 2 ms later; (c) effect of magnifying gray difference of picture by 10×

Fig. 3. Influence of presence or absence of ambient light on phase under different phase shift steps. (a) 3 steps phase shifting; (b) 18 steps phase shifting

Fig. 4. Processing results of picture pixels. (a) Average gray-scale sequence; (b) Fourier transform results (local)

Fig. 5. Equation curve of average grayscale with time

Fig. 6. Schematic of phase compensation process

Fig. 7. Aimulate dephasing results of ambient light and noise images at different times and with different intensity noises. 0 ms, (a) 1 pixel intensity noise, (b) 0.4 pixel intensity noise; 4 ms, (c) 1 pixel intensity noise, (d) 0.4 pixel intensity noise; (e) grating fringe pattern at 10 ms; (f) phase of grating fringe pattern

Fig. 8. Phase error comparison before and after algorithm is processed under influence of different noise levels. (a) Noise variance is 0.4 pixel intensity; (b) noise variance is 1.0 pixel intensity

Fig. 9. Three-dimensional reconstruction of image and point cloud. (a) Plaster portrait collected by high-speed camera; (b) phase of plaster portrait; 18 steps phase shifting collection, (c) no ambient light source, (d) fluorescent lamp situation; 3 steps phase shifting collection, (e) no ambient light source, (f) fluorescent lamp situation

Fig. 10. Standard spherical point cloud and fitting residual distribution. Without ambient light source, (a) 18 steps phase shifting reconstruction results, (c) 3 steps phase shifting reconstruction results; with ambient light source, (b) 3 steps phase shifting and reconstruction by using proposed algorithm after compensation results, (d) 3 steps phase shifting reconstruction results