Phase unwrapping of interferogram with obscurations in phase-shifting interferometry

A new phase unwrapping method based on qualitymap-guided path-integralmethod is presented to deal with the discontinuous unwrapping result of the interferogram with obscurations in phase-shifting interferometry. First, the obscured regions are filled according to the texture feature of wrapped phase data in adjacent valid regions by image repair. The valid regions are connected together in this way and thus path-integral phase unwrapping can be conducted through different valid regions. To ensure the same addition or subtraction of integral multiple of 2π between wrapped phase in the same fringe order but different valid regions, a path-integral phase unwrapping method based on a new quality map is proposed. The new quality map can lead the integral path to follow the minimum phase variation direction through the filled regions. The unwrapping result shows that, the presented method is effective to avoid the global error of integral multiple of 2π between different valid regions in phase unwrapping of interferogram with obscurations in phase-shifting interferometry.