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 2π-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 π, 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.
© 2002 Optical Society of America
Xiao Yuan He, Xin Kang, Cho Jui Tay, Chenggen Quan, and Huai Min Shang, "Proposed Algorithm for Phase Unwrapping," Appl. Opt. 41, 7422-7428 (2002)