Fig. 1. Experimental setup for multi-camera three-dimensional shape measuring system using digital fringe projection techniques

Fig. 2. Directional circular pattern for planar calibration target

Fig. 3. (a)-(d) Images of the flexible calibration target grabbed by different cameras. (a) Camera 1; (b) camera 2; (c) camera 3; (d) camera 4. (e)-(h) Images grabbed by camera 1 of the flexible calibration target with different shapes. (e) Shape 1; (f) shape 2; (g) shape 3; (h) shape 4

Fig. 4. Calibration error diagram from camera 2 to camera 1 in quaternary quadratic model

Fig. 5. Measurement results of 4 different polynomial models. (a) Ternary quadratic model; (b) ternary cubic model; (c) quaternary quadratic model; (d) quaternary cubic model

Fig. 6. Measurement results of different FOV overlapping. (a) 1/2; (b)1/3; (c) 1/4; (d) 1/6

Fig. 7. Image of multiple objects to be measured

Fig. 8. 3D reconstruction images. (a) Camera 1; (b) camera 2; (c) camera 3; (d) camera 4; (e) merged image

Fig. 9. Step standard block and its size

Fig. 10. 3D reconstruction image of the step standard block by camera 2 using (a) method 1 and (b) method 2

Fig. 11. Standard ball

Fig. 12. Fitted spheres based on the spherical crown point cloud