The fringe orientation angle provides useful information for many fringe-pattern-processing techniques. From a single normalized fringe pattern (background suppressed and modulation normalized), the fringe orientation angle can be obtained by computing the irradiance gradient and performing a further arctangent computation. Because of the 180° ambiguity of the fringe direction, the orientation angle computed from the gradient of a single fringe pattern can be determined only modulo π. Recently, several studies have shown that a reliable determination of the fringe orientation angle modulo 2π is a key point for a robust demodulation of the phase from a single fringe pattern. We present an algorithm for the computation of the modulo 2π fringe orientation angle by unwrapping the orientation angle obtained from the gradient computation with a regularized phase tracking method. Simulated as well as experimental results are presented.
© 2002 Optical Society of America
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