Theoretical analysis for moiré deflectometry from diffraction theory

• DOI: 10.1364/josaa.26.000882
• Publication Date: 2009-03-19T21:32:52Z
• Authors: Yang Song; Yun Yun Chen; Anzhi He; Zhimin Zhao
• Keywords: Moiré pattern; Shearing (physics)

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