Binary coded triangular fringes for 3-D surface-shape measurement.

We present a method for synthesizing triangular intensity fringes as a way to solve the problems caused by projector/camera gamma nonlinearity in triangular-pattern phase-shifting profilometry. The fringe generation technique consists of projecting and acquiring a temporal sequence of strictly binary color patterns (code gray), whose (adequately weighted) average leads to triangular fringe patterns with the required number of bits, which allows a reliable three-dimensional profile reconstruction using these methods. Validation experiments are presented.

[1]  Jonathan Kofman,et al.  Real-time full-field 3-D surface-shape measurement using off-the-shelf components and a single processor , 2007, Sixth International Conference on 3-D Digital Imaging and Modeling (3DIM 2007).

[2]  Robert A. Hummel,et al.  Experiments with the intensity ratio depth sensor , 1985, Comput. Vis. Graph. Image Process..

[3]  Gastón A. Ayubi,et al.  Color encoding of binary fringes for gamma correction in 3-D profiling. , 2012, Optics letters.

[4]  J. Kofman,et al.  Comparison of linear and nonlinear calibration methods for phase-measuring profilometry , 2007 .

[5]  Jonathan Kofman,et al.  Two-step triangular-pattern phase-shifting method for three-dimensional object-shape measurement , 2007 .

[6]  Song Zhang.  Recent progresses on real-time 3D shape measurement using digital fringe projection techniques , 2010 .

[7]  N. Otsu.  A threshold selection method from gray level histograms , 1979 .

[8]  S. Inokuchi,et al.  Three-dimensional surface measurement by space encoding range imaging , 1985 .

[9]  Jason Geng,et al.  Structured-light 3D surface imaging: a tutorial , 2011 .

[10]  Jonathan Kofman,et al.  Multiple-step triangular-pattern phase shifting and the influence of number of steps and pitch on measurement accuracy. , 2007, Applied optics.

[11]  Chad English,et al.  Error compensation in two-step triangular-pattern phase-shifting profilometry , 2008 .

[12]  Song Zhang,et al.  High-resolution, real-time 3D absolute coordinate measurement based on a phase-shifting method. , 2006, Optics express.

[13]  C. Waddington,et al.  Analysis of measurement sensitivity to illuminance and fringe-pattern gray levels for fringe-pattern projection adaptive to ambient lighting , 2010 .

[14]  Chad English,et al.  Intensity-ratio error compensation for triangular-pattern phase-shifting profilometry. , 2007, Journal of the Optical Society of America. A, Optics, image science, and vision.

[15]  Fu-Pen Chiang,et al.  High-speed 3-D shape measurement based on digital fringe projection , 2003 .