For temporal phase unwrapping in phase measuring profilometry, it has recently been reported that two phases with co-prime frequencies can be absolutely unwrapped using a look-up table; however, frequency selection and table construction has been performed manually without optimization. In this paper, a universal phase unwrapping method is proposed to unwrap phase flexibly and automatically by using geometric analysis, and thus we can programmatically build a one-dimensional or two-dimensional look-up table for arbitrary two co-prime frequencies to correctly unwrap phases in real time. Moreover, a phase error model related to the defocus effect is derived to figure out an optimal reference frequency co-prime to the principal frequency. Experimental results verify the correctness and computational efficiency of the proposed method.
Digital Object Identifier (DOI)
National Natural Science Foundation of China (NSFC #61473198); Science and Technology Support Program of Sichuan Province, China (#2018GZ0198); Science and Technology Support Program of Chengdu City, China (#2018-YFYF-00029-GX); Intel Corporation and the National Science Foundation (1539157).
Song, Jianwen; Lau, Daniel L.; Ho, Yo-Sung; and Liu, Kai, "Automatic Look-Up Table Based Real-Time Phase Unwrapping for Phase Measuring Profilometry and Optimal Reference Frequency Selection" (2019). Electrical and Computer Engineering Faculty Publications. 36.