Fig. 1. Principle of defocusing projection. (a) Defocusing imaging; (b) defocusing area division

Fig. 2. Binary fringe with different defocusing level. (a) Original fringe; (b)‒(d) binary images with increasing defocusing level

Fig. 3. Property of square wave signal. (a) Harmonic distribution; (b) harmonic attenuation

Fig. 4. Fliter with different Guassion kernels

Fig. 5. Comparison before and after filtering. (a) Pre-defocus signal; (b) defocused signal; (c) frequency spectrum of Fig.5 (a); (d) frequency spectrum of Fig.5 (b)

Fig. 6. Schematic of TRP chip^[39]. (a) -17°; (b) +17°

Fig. 7. Frequency-spectrum diagram of SPWM fringe with different modulation frequency. (a) k=9; (b) k=13

Fig. 8. Bayer dithering technique for sinusoidal image^[81]. (a) Original sinusoidal image; (b) image obtained by Bayer dithering for Fig.8(a)

Fig. 9. Framework of Bayer dithering optimization algorithm^[88]

Fig. 10. Schematic of S-SD method^[97]. (a) Scanning sequence of S-SD; (b) error diffusion

Fig. 11. Combining binary fringe projection process^[106]