Author Affiliations
College of Electronics and Information Engineering, Sichuan University, Chengdu, Sichuan 610065, Chinashow less
Fig. 1. Generated projection patterns. (a) Embedded speckle pattern; (b) one of composite fringe patterns
Fig. 2. Schematic of preparation before measurement. (a) Principle diagram of measuring system; (b) calculated wrapped phase and reference speckle; (c) wrapped phase maps at different heights for building LUT; (d) establishment of wrapped phase-to-height LUT of one pixel along light ray l; (e) reference speckle images at different heights for saving in advance
Fig. 3. Comparison of reconstruction results and error rates between NCC and ZNCC. (a) Plaster model and corresponding speckle pattern; 3D measurement results with (b) NCC and (c) ZNCC; (d) (e) corresponding error point distributions
Fig. 4. Principle diagram of height reconstruction. (a) Principle diagram of measuring system; (b) corresponding wrapped phase and speckle; (c) several candidate heights from LUT; (d) speckle correlation computation between reference speckle subareas corresponding to candidate heights and target speckle subarea centered on point S'p(x,y)
Fig. 5. Experimental setup of 3D measuring system
Fig. 6. Experimental results of accuracy evaluation. (a) Workpieces to be measured; (b) 3D reconstruction results and height differences among three planes; (c) error distributions
Fig. 7. 3D reconstruction results of single object. (a) Plaster model; (b) corresponding wrapped phase map and speckle pattern; (c) 3D measurement result before compensation and enlarged detail chart; (d) final 3D measurement result and enlarged detail chart
Fig. 8. 3D reconstruction results of isolated objects. (a) Portrait plaster model and clock model; (b) corresponding wrapped phase maps and speckle patterns; (c) 3D measurement results before compensation and enlarged detail charts; (d) final 3D measurement results and enlarged detail charts
Fig. 9. 3D measurement of dynamic scene. (a) Wrapped phase maps at different moments; (b) speckle patterns at different moments; (c) corresponding 3D reconstruction results
Function | All 160 reference speckle patternsinvolved for correlation | Only 10 reference speckle patternsinvolved for correlation | 10 reference speckle patternsfor proposed method |
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NCC | 23.94 | 2.05 | 1 | ZNCC | 39.15 | 3.38 | 1.63 |
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Table 1. Time-consuming ratio of speckle correlation computation in each case