A fast phase unwrapping method based on region-division

Phase unwrapping is a vital part of optical measurement technology. The path-following method based on quality map, the mainstream technology in single fringe-pattern phase unwrapping, can suppress the error propagation of phase unwrapping effectively. However, the time consumption of this technology will increase significantly along with the increasing of pixels in a fringe pattern. For this reason, a phase unwrapping method based on region division was proposed, through bidimensional sinusoids-assisted empirical mode decomposition (BSEMD). In this method, the problematic regions where the phase unwrapping error is easy to occur such as object edge and local shadow will be divided. In these problematic regions, the quality-guided phase unwrapping method will be applied, where the instantaneous frequencies acquired in the process of extracting wrapped phase are taken as quality map. Then flood fill algorithm will be applied in the rest regions directly. Through simulation and experiment, the proposed method greatly improves the processing speed while ensuring the accuracy.