Calibration of 3D surface profilometry using digital fringe projection

An effective calibration method, by minimizing measurement errors, has been developed to increase the accuracy of 3D profilometry using digital fringe projection and phase-shifting method. In digital fringe projection, the image intensity and distribution of the sinusoidal fringe patterns projected on the measured surface can be critically affected by lens distortions and image aberrations. The phase difference calculated by the phase-shift principle can be significantly influenced by these error sources and become nonlinear to the optical phase difference (OPD) existing between the surface profiles. This paper demonstrates a 3D calibration method developed to obtain accurate system parameters for 3D surface measurement. The calibration method utilizes a known accurate 3D calibrating block and projection mathematical models for identification of the system parameters by means of least-squares minimization. Accurate clouds of 3D data points can be obtained by a 3D mapping method between the object space and the image coordinates incorporating the phase difference. The measurement accuracy of surface contouring can be maintained well within 2% of the overall measurement range. Verified with the experimental results, the proposed calibration method can effectively reduce more than 60% of the maximum measured error in comparison with the traditional phase-conversion method.

[1]  M. Takeda,et al.  Fourier transform profilometry for the automatic measurement of 3-D object shapes. , 1983, Applied optics.

[2]  J C Wyant,et al.  Two-wavelength phase shifting interferometry. , 1984, Applied optics.

[3]  V. Srinivasan,et al.  Automated phase-measuring profilometry of 3-D diffuse objects. , 1984, Applied optics.

[4]  Roger Y. Tsai,et al.  A versatile camera calibration technique for high-accuracy 3D machine vision metrology using off-the-shelf TV cameras and lenses , 1987, IEEE J. Robotics Autom..

[5]  Larry J. Hornbeck,et al.  Digital Light Processing for high-brightness high-resolution applications , 1997, Electronic Imaging.

[6]  Fu-Pen Chiang,et al.  Color-encoded digital fringe projection technique for high-speed three-dimensional surface contouring , 1999 .

[7]  K. Iwata,et al.  Profile measurement taken with liquid-crystal gratings. , 1999, Applied optics.

[8]  Mumin Song,et al.  Overview of three-dimensional shape measurement using optical methods , 2000 .

[9]  Seung-Woo Kim,et al.  Phase-shifting projection moire for out-of-plane displacement measurement , 2001, International Conference on Experimental Mechanics.

[10]  David R Burton,et al.  Technique for phase measurement and surface reconstruction by use of colored structured light. , 2002, Applied optics.

[11]  Qingying Hu,et al.  Calibration of a three-dimensional shape measurement system , 2003 .

[12]  Peisen S. Huang,et al.  Error compensation for a three-dimensional shape measurement system , 2003 .

[13]  Liang-Chia Chen,et al.  Miniaturized 3D surface profilometer using digital fringe projection , 2005 .