1. Comparative study of sampling moiré and windowed Fourier transform techniques for demodulation of a single-fringe pattern
- Author
-
Qian Kemao, Nimisha Agarwal, Shien Ri, and Qinghua Wang
- Subjects
Noise (signal processing) ,business.industry ,Phase (waves) ,Wavelet transform ,02 engineering and technology ,Moiré pattern ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Structured-light 3D scanner ,010309 optics ,symbols.namesake ,Fourier transform ,Optics ,Sampling (signal processing) ,0103 physical sciences ,symbols ,Demodulation ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Engineering (miscellaneous) ,Algorithm ,Mathematics - Abstract
Phase measurement techniques using a single-shot carrier fringe pattern play an important role in optical science and technology and have been widely used for various applications. In this paper, we focus on the comparative study of two major fringe analysis techniques, the sampling moire (SM) and the windowed Fourier transform (WFT). While SM converts a single-fringe pattern to multiple phase-shifted moire fringe patterns to extract the phase information in the spatial domain, WFT obtains the phase information in the windowed Fourier domain; thus, the two methods look entirely different. We evaluate the phase extraction errors of SM and windowed Fourier ridges (WFRs) as a typical WFT method for both linear and nonlinear phases with/without noise against the reference Fourier transform (FT) technique. For the simulated fringe patterns with linear or nonlinear phase and different random noise level, all the methods have high phase extraction accuracies. For a real experiment with more complicated phase and discontinuities, SM and WFR, both local methods, yield quite similar results and outperform FT.
- Published
- 2019