Wang Haixia, Kemao Qian
School of Computer Engineering, Nanyang Technological University, Singapore.
Appl Opt. 2012 Feb 1;51(4):413-21. doi: 10.1364/AO.51.000413.
Fringe patterns produced by various optical interferometric techniques encode information such as shape, deformation, and refractive index. Denoising and demodulation are two important procedures to retrieve information from a single closed fringe pattern. Various existing denoising and demodulation techniques require fringe direction/orientation during the processing. Fringe orientation is often easier to obtain but fringe direction is needed in some demodulation techniques. A quality-guided orientation unwrapping scheme is proposed to estimate direction from orientation. Two techniques, one based on windowed Fourier ridges and the other based on fringe gradient, are proposed for the quality-guided orientation unwrapping scheme. The direction qualities are compared for both simulated and experimental fringe patterns. Their application to demodulation technique is also given.
各种光学干涉测量技术产生的条纹图案编码了诸如形状、变形和折射率等信息。去噪和解调是从单个封闭条纹图案中检索信息的两个重要过程。现有的各种去噪和解调技术在处理过程中都需要条纹方向/取向。条纹取向通常更容易获得，但在某些解调技术中需要条纹方向。提出了一种基于质量引导的取向展开方案，用于从取向估计方向。针对基于质量引导的取向展开方案，提出了两种技术，一种基于加窗傅里叶脊，另一种基于条纹梯度。对模拟条纹图案和实验条纹图案的方向质量进行了比较。还给出了它们在解调技术中的应用。
