Direct demodulation of closed-fringe interferograms based on active contours

Abstract

We demonstrate a method to directly demodulate closed-fringe interferograms using a kind of active contour called a snake. Thismethodcanbeusedtodemodulateasingleclosed-fringeinterferogram when itsbackground illumination and/or contrast terms have a spatial frequency similar to the spatial frequency of the equivalent normalized interferogram. Among other cases, this problematic usually appearsin interferometry when spurious reflection appears in the interferogram. In these situations, typical Fourier-based methods are of no help. We show a set of simulations and experimental results that prove the effectiveness of the proposed method. © 2010 Optical Society of America.