Abstract

Theories of moiré deflectometry are presented based on scalar diffraction theory. It is shown that the moiré effect is not a pure geometric phenomenon but actually the result of multishearing interference. By performing zeroth-order or first-order filtering, the field in the plane of observation is seen to be the result of double- or triple-shearing interference, respectively. With first-order filtering, the intensity distribution is proved to be a strict cosinusoidal intensity distribution, and the diffraction effect, which depends on the distance between two gratings, affects just the phase shift of the moiré fringes. Compared with previous research, a more precise relation between the unwrapped phase and the deflection angles is obtained. The results will be very useful for image processing of moiré patterns with Fourier transform profilometry and phase-shift methods.

© 2009 Optical Society of America

Diffraction effects in moiré deflectometry

E. Keren and O. Kafri
J. Opt. Soc. Am. A 2(2) 111-120 (1985)

Theoretical analysis for moiré effect of circular gratings for volume optical computerized tomography

Jia Wang, Yang Song, Zhen-hua Li, Nan Sun, and An-zhi He
J. Opt. Soc. Am. A 29(8) 1686-1693 (2012)

Investigation of phase object trace duplication in moiré deflectometry

Mohammad Ahmadi and Khosro Madanipour
Appl. Opt. 55(36) 10370-10374 (2016)

Comprehensive study of moiré deflectometry based on diffraction order filtering of fringes

Sara Vosough Yazdani, Mohammad Ahmadi, and Khosro Madanipour
Appl. Opt. 62(27) 7157-7162 (2023)

Effect of diffraction on the moiré image. I. Theory

Ezra Bar-Ziv
J. Opt. Soc. Am. A 2(3) 371-379 (1985)