Spatiotemporal Phase-Shifting Method for Robust Phase Analysis of Noisy Fringe Pattern

Abstract

Phase analysis of fringe pattern technique has been widely used for three-dimensional shape and deformation measurement by fringe projection method, precise inspection of optical components by various interferometry, etc. To analyze the phase distribution of fringe pattern, more than 80 phase analysis methods have been proposed by many researchers in this research field [1]. For instance, a Fourier transform [2], a wavelet transform, a windowed Fourier transform, and a sampling Moiré method [3] have been developed from a single-shot image by using the intensity information in the spatial domain. In addition, the phase-shifting method (PSM) [4], which uses multi-frame phase-shifted fringe patterns is mostly used to analyze the phase distribution by using the intensity information in the temporal domain. However, these techniques only use one-dimensional intensity information in the spatial- or temporal-domains. For this reason, the analyzed phase distribution for noisy fringe pattern remains large measurement error due to the low reflectance of the object and the random noise of the camera.