A new method for phase extraction from a single fringe pattern

Abstract

A new technique for phase extraction from a single fringe-pattern image is presented. The algorithm locates the fringe maxima (assigned value 1) and minima (assigned value - 1), and converts the intermediate gray-values into values between - 1 and 1 using linear interpolation. A wrapped phase map is demodulated from a single fringe-pattern and the phase values are computed using an atan mode rather than an atan2 mode. Using the new algorithm wrapped phase values can be efficiently extracted from a single fringe pattern without the need for phase-shifting or carrier fringes. Phase extraction is carried out without the need for assigning fringe orders and distinction for a peak and a trough. The method can be applied to the study of transient events. Experimental results are presented to demonstrate the validity of the method. © 2004 Elsevier B.V. All rights reserved.