A fringe period unwrapping technique for digital fringe profilometry based on spatial shift estimation

et al. 2014

J. Electron. Imaging

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An approach is presented to solve the problem of spatial shift wrapping associated with spatial shift estimation-based fringe pattern profilometry (FPP). This problem arises as the result of fringe reuses (that is, use of fringes with periodic light intensity variance), and the spatial shift can only be identified without ambiguity within the range of a fringe width. It is demonstrated that the problem is similar to the phase unwrapping problem associated with the phase-detection-based FPP, and the proposed method is inspired by the existing ideas of using multiple images with different wavelengths proposed for phase unwrapping. The effectiveness of the proposed method is verified by comparing experimental results against several objects, with the last object consisting of more complex surface features. We conclude by showing that our method is successful in reconstructing the fine details of the more complex object. Abstract. An approach is presented to solve the problem of spatial shift wrapping associated with spatial shift estimation-based fringe pattern profilometry (FPP). This problem arises as the result of fringe reuses (that is, use of fringes with periodic light intensity variance), and the spatial shift can only be identified without ambiguity within the range of a fringe width. It is demonstrated that the problem is similar to the phase unwrapping problem associated with the phase-detection-based FPP, and the proposed method is inspired by the existing ideas of using multiple images with different wavelengths proposed for phase unwrapping. The effectiveness of the proposed method is verified by comparing experimental results against several objects, with the last object consisting of more complex surface features. We conclude by showing that our method is successful in reconstructing the fine details of the more complex object.

“…24, and it is unwrapped using the method in Ref. 20. In contrast, the multiple-wavelength algorithm proposed is also used.…”

Section: Experiments and Resultsmentioning

confidence: 99%

Section: Multiple-wavelength Spatial Shift Unwrappingmentioning

confidence: 99%

Section: Multiple-wavelength Spatial Shift Unwrappingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Spatial shift unwrapping for digital fringe profilometry based on spatial shift estimation

et al. 2014

J. Electron. Imaging

Self Cite

“…In order to work out how to unwrap the spatial shift, a simple spatial shift unwrapping method has been proposed in [25], which unwraps the spatial shift using the neighbourhood pixels. However, this method has the limitation which cannot retrieve the correct shift distribution if the value difference of neighbourhood pixels is greater than λ/2.…”

Section: Multi-wavelength Spatial Shift Unwrapping Algorithmmentioning

confidence: 99%

A multiple wavelength unwrapping algorithm for digital fringe profilometry based on spatial shift estimation

et al. 2014

SPIE Proceedings

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In this paper, a new approach is presented for solving the problem of spatial shift wrapping associated with Spatial Shift Estimation (SSE)-based Fringe Pattern Profilometry (FPP). The problem arises as the result of fringe reuse (that is, fringes periodic light intensity variance), and the spatial shift can only be identified without ambiguity with the range of a fringe width. It is demonstrated that the problem is similar to the phase unwrapping problem associated with the phase detection based FPP, and the proposed method is inspired by the existing ideas of using multiple images with different wavelengths proposed for phase unwrapping. The effectiveness of the proposed method is verified by experimental results on an object with complex surface shape. 2014 SPIE.

3D shape measurement based on projection of triangular patterns of two selected frequencies

et al. 2014

Opt. Express

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In this paper, a temporal shift unwrapping technique is presented for solving the problem of shift wrapping associated with spatial shift estimation (SSE)-based fringe pattern profilometry (FPP). Based on this technique, a novel 3D shape measurement method is proposed, where triangular patterns of two different spatial frequencies are projected. The patterns of the higher frequency are used to implement the FPP, and the one with lower frequency is utilized to achieve shift unwrapping. The proposed method is able to solve the shift unwrapping problem associated with the existing multi-step triangular pattern FPP by projection of an additional fringe pattern. The effectiveness of the proposed method is verified by experimental results, where the same accuracy as existing multi-step triangular pattern FPP can be achieved, but enabling the measurement of objects with complex surface shape and high steps. Disciplines Engineering | Science and Technology Studies Abstract:In this paper, a temporal shift unwrapping technique is presented for solving the problem of shift wrapping associated with spatial shift estimation (SSE)-based fringe pattern profilometry (FPP). Based on this technique, a novel 3D shape measurement method is proposed, where triangular patterns of two different spatial frequencies are projected. The patterns of the higher frequency are used to implement the FPP, and the one with lower frequency is utilized to achieve shift unwrapping. The proposed method is able to solve the shift unwrapping problem associated with the existing multi-step triangular pattern FPP by projection of an additional fringe pattern. The effectiveness of the proposed method is verified by experimental results, where the same accuracy as existing multi-step triangular pattern FPP can be achieved, but enabling the measurement of objects with complex surface shape and high steps. 21739-21747 (2011). 6. X. Su, L. Su, W. Li, and L. Xiang, "New 3D profilometry based on modulation measurement," Proc. SPIE 3853, 1-7 (1998). 7. S. Toyooka and M. Tominga, "Spatial fringe scanning for optical phase measurement," Opt. Commun. 51(2), 68-70 (1984). 8. S. Toyooka and Y. Iwaasa, "Automatic profilometry of 3-D diffuse objects by spatial phase detection," Appl.Opt. 25(10), 1630-1633 (1986). 9. R. Rodríguez-Vera and M. Servin, "Phase locked loop profilometry," Opt. Laser Technol. 26(6), 393-398 (1994). 10. D. M. Meadows, W. O. Johnson, and J. B. Allen, "Generation of surface contours by moiré patterns," Appl. Opt. 9(4), 942-947 (1970). 11. A. Asundi and Z. Wensen, "Unified calibration technique and its applications in optical triangular profilometry," Appl. Opt. 38(16), 3556-3561 (1999). 12. P. Huang, Q. Ho, F. Jin, and F. Chiang, "Colour-enhanced digital fringe projection technique for high-speed 3-D surface contouring," Opt. Eng. 38(6), 1065-1071 (1999). 13. Z. Zhang, C. E. Towers, and D. P. Towers, "Robust color and shape measurement of full color artifacts by RGB fringe projection," Opt. Eng. 51(2), 021109 (2012). 14. J. Guo, X. Pen...