Fig. 1. Schematic diagram of 3D imaging technique based on Gray-coded structured illumination

Fig. 2. Direct Gray-coded coding technique. (a) Projected patterns; (b) Decoding process of Gray code; (c) Zero-crossing edge detection method; (d) Positive and negative edge detection method; (e) Improved zero-crossing edge detection method

Fig. 3. Gray-coded-aided line shifting technique. (a) Projected line-shifting patterns; (b) Projected Gray-coded patterns; (c) Decoding process; (d) Peak detection of the line

Fig. 4. Gray-coded-aided stripe edge shifting technique. (a) Projected stripe-edge-shifting patterns; (b) Projected Gray-coded patterns; (c) Decoding process

Fig. 5. Experimental results of the Gray-coded-aided stripe edge shifting technique ^[36]. (a) Microchip; (b) Measuring result of a microchip; (c) Coin; (d) Measuring result of a coin

Fig. 6. Experimental results of the improved Gray-coded-aided stripe edge shifting technique ^[38]. (a) Captured fringe pattern with low exposure time; (b) Captured fringe pattern with high exposure time; (c) Generated fringe pattern using HDR technique; (d) Measuring result of the metal surface

Fig. 7. Gray-coded-aided phase shifting technique. (a) Projected phase-shifting patterns; (b) Projected Gray-coded patterns; (c) Decoding process

Fig. 8. Decoding process of the complementary Gray codes

Fig. 9. Experimental results of the complementary Gray-coded-aided phase shifting technique. (a) Experimental result of the traditional Gray-coded-aided phase shifting technique; (b) Partial enlargement of (a); (c) Experimental result of the complementary Gray-coded-aided phase shifting technique; (d) Partial enlargement of (c)

Fig. 10. Representative techniques of fringe binarization. (a) Binary square wave; (b) Optimal pulse width modulation; (c) Two dimensional dithering binarization

Fig. 11. Schematic diagram of the cyclic complementary Gray-coded-aided phase shifting technique

Fig. 12. Experimental results of the cyclic complementary Gray-coded-aided phase shifting technique. (a) 3D reconstruction of the impact process of Newton’s cradle; (b) Velocity change of the left and right balls in the impact process

Fig. 13. Schematic diagram of the shifting Gray-coded-aided phase shifting technique

Fig. 14. Experimental results of reconstructing the simple pendulum swing using shifting Gray-coded-aided phase shifting technique

Fig. 15. Experimental results of reconstructing the collapsing building blocks using shifting Gray-coded-aided phase shifting technique

Fig. 16. Ternary Gray-coded-aided phase shifting technique. (a) Projected ternary Gray-coded patterns; (b) Projected binarized phase-shifting patterns; (c) Decoding process of ternary Gray-code

Fig. 17. Schematic diagram of the light plane method

Fig. 18. Schematic diagram of the method based on inverse projector calibration

Fig. 19. Schematic diagram of the implicit calibration method