PATH-INDEPENDENT PHASE UNWRAPPING OF SUBSAMPLED PHASE MAPS

A technique for unwrapping subsampled phase maps is presented. The sub sampled phase map is obtained by standard phase-shifting methods that use subsampled interferograms. The technique then estimates the wrappe d local curvature of the subsampled phase map. This local curvature is then low-pass filtered with a free-boundary low-pass filter to reduce phase noise. Finally, the estimated local curvature of the wave front is integrated by the use of a least-squares technique to obtain the s earched continuous wave front. (C) 1996 Optical Society of America.