A phase unwrapping method suitable for high frequency fringe based on edge feature

Abstract Phase unwrapping (PU) technology is an important component of fringe projection profilometry (FPP). The key of PU is to obtain accurate fringe order. The existing PU methods are hard to make a tradeoff between efficiency and accuracy. To reduce the number of stripes, a phase unwrapping method based on edge feature (EFPU) is proposed. For this method, we make full use of the properties of wrapped phase map rather than auxiliary fringe patterns. We firstly analyze an edge detection operator suitable for wrapped phase map. Furthermore, in order to improve the stability of the proposed method, the edge correction method is proposed to correct edge point and the reverse correction method is presented to further optimize the fringe order. The experimental results show that the absolute phase map obtained by EFPU is similar to that of multi-wavelength phase-shifting (MWPS) method, but the number of fringe patterns is only one-third of MWPS.