HIGH-SPEED FRINGE ANALYSIS BY USING STAIR-SHAPED VIRTUAL GRATING DEMODULATION

This article describes a novel fringe analysis technique using stair-s haped virtual grating demodulation algorithm for extracting the phase information from a single fringe pattern. In contrast to the Fourier t ransform technique and quadrature multiplicative moire method, the new method processes a fringe pattern in the integer signal domain instea d of the frequency domain and real-signal domain. The spatial carrier of fringe image is not limited to any particular frequency as long as if fulfills the sampling theorem. The errors analysis of this techniqu e is conducted by computer simulation and experiments. (C) 1997 Elsevi er Science Ltd.