PHASE-STEP INSENSITIVE ALGORITHMS FOR PHASE-SHIFTING INTERFEROMETRY

Two novel phase extraction algorithms, in which step sizes need not be known or equal, are described. One algorithm requires a minimum of five interferograms from which intensity offset and intensity modulation are calculated at each pixel and the relative phase is calculated for all pixels with respect to a reference pixel. The other algorithm requires two phase stepping mechanisms and a minimum of ten interferograms. The intensity characteristics and reference phase step are calculated at each pixel and a previously published algorithm is used for the final phase calculation.