Abstract
In phase-measurement profilometry (PMP), the gamma effect can cause severe nonlinear distortion of the phase pattern (i.e., water ripples on the surface profile). Gamma correction is an effective method to eliminate the gamma effects of commercial projectors. However, projector defocusing on the suppression of higher harmonics inevitably results in an estimated gamma deviation from the true value. In this study, gamma mapping is constructed using the duty ratio (DR) to code the chord distribution of the simulated distorted phase while considering projector defocusing. With the known gamma mapping, the accurate gamma is calculated by DR coding of the actual distorted phase under projector defocusing. Simulated experiments verified that the relative errors of the gamma calculated by the proposed method under different degrees of defocus were less than 3.5%. Furthermore, the experimental results demonstrate that the proposed gamma calculation method is robust to the defocus effect of the projector and that a smoother surface can be reconstructed after gamma correction.
© 2022 Optica Publishing Group
Full Article | PDF ArticleMore Like This
Lin Wang, Yuetong Zhang, Lina Yi, Xin Hao, Meiyi Wang, and Xiangjun Wang
J. Opt. Soc. Am. A 39(11) 1983-1991 (2022)
Shaoyan Gai, Feipeng Da, and Chao Liu
Appl. Opt. 57(35) 10290-10299 (2018)
Xu Zhang, Limin Zhu, Youfu Li, and Dawei Tu
J. Opt. Soc. Am. A 29(6) 1047-1058 (2012)