He Xiao Yuan, Kang Xin, Tay Cho Jui, Quan Chenggen, Shang Huai Min
Department of Engineering Mechanics, Southeast University, 2 Sipailou Street, Nanjing 210096, China.
Appl Opt. 2002 Dec 10;41(35):7422-8. doi: 10.1364/ao.41.007422.
A new, to our knowledge, two-dimensional phase-unwrapping algorithm is proposed. The algorithm, which is based on the global continuity of physical information (e.g. the three-dimensional surface profile of an object) being measured, uses the principle of least-phase difference to rectify errors caused by an erroneous 2pi-phase jump in the initial unwrapped phase map obtained by the conventional phase-unwrapping method. Experimental results show that the proposed algorithm works well on a phase map that contains error sources, such as noises, phase discontinuity of more than pi, and insufficient sampling. Moreover, the algorithm is most suitable for unwrapping a phase map generated during shape measurement with a step-change surface on the test object, which is usually a critical problem in shape measurement.
