Song Yang, Chen Yun Yun, He Anzhi, Zhao Zhimin
Department of Information Physics and Engineering, Nanking University of Science and Technology, Nanking 210094 China.
J Opt Soc Am A Opt Image Sci Vis. 2009 Apr;26(4):882-9. doi: 10.1364/josaa.26.000882.
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.
基于标量衍射理论提出了莫尔偏折术的理论。结果表明，莫尔效应并非纯粹的几何现象，而是多剪切干涉的结果。通过进行零阶或一阶滤波，观察平面内的场分别被视为双剪切或三剪切干涉的结果。采用一阶滤波时，强度分布被证明是严格的余弦强度分布，而取决于两个光栅间距的衍射效应仅影响莫尔条纹的相移。与先前的研究相比，得到了展开相位与偏转角之间更精确的关系。这些结果对于利用傅里叶变换轮廓术和相移方法对莫尔条纹进行图像处理将非常有用。
