Phase invalidity identification framework with the temporal phase unwrapping method

摘要

Phase retrieval from fringe patterns is widely used in optical metrology. In profilometry for example, precise phase values allow three-dimensional coordinate data with higher accuracy to be determined. The phase-shifting method coupled with temporal phase unwrapping provides not only the unwrapped phase, but also gives the modulation map, root mean square errors of least-squares fitting, and phase relationship between two neighboring pixels, which can be used for phase error identification. A practical invalid phase identification framework is presented to automatically identify the invalid measuring points with threshold selection and criterion testing. Experimental results show the practical feasibility of the proposed framework.