Fast quality-guided flood-fill phase unwrapping algorithm for three-dimensional fringe pattern profilometry

A fast quality-guided flood-fill phase unwrapping algorithm is proposed for real-time 3D Fringe Pattern Profilometry (FPP) system. The proposed approach consists of three steps. First, based on the phase maps acquired by phase shift profilometry (PSP) techniques, a quality map is generated according to the phase variance adjacent pixels on the wrapped phase map. According to the quality map, the phase map is divided into several parts which are categorised as either rapid phase changing areas or smooth phase changing areas. Then quality-guided flood-fill phase unwrapping algorithm is applied to rapid phase changing areas and non-guided path-following algorithm is used in the smooth phase changing area. The proposed approach is much faster than the conventional non-guided path-following algorithm, and it is more robust than the non-guided path-following algorithm. Experiments are carried out to verify the performance.