在光学干涉测量技术中, 准确地实现条纹正则化是提取条纹图中的相位信息的前提. 文中基于双重正交带通滤波器的正则优化法, 提出了以条纹密度信息为质量评估标准来引导条纹正则化的优化方法, 包含条纹图局部优化与整体优化两部分, 是对双重正交带通滤波器的正则化方法的改进. 首先以条纹背景强度和振幅具有的局部线性与连续性特征设计能量函数, 并通过最小化能量函数获取背景强度和条纹振幅的值; 然后根据高低密度区域条纹的分析, 提出密度对正则化过程的导向作用以及局部优化的可行性.实验结果表明, 以密度为导向的条纹正则优化法具有均方误差低、抗噪性高等优点; 提出的条纹正则优化方法在操作上不需要对噪声严重的条纹图进行除噪预处理, 对背景强度与振幅的线性与非线性变化可同时处理, 具有较高的条纹处理效率和准确性, 可应用于复杂的条纹图正则化处理.
Fringe pattern normalization is an essential preprocessing step for the data analysis of the optical inter-ferometric techniques. A novel density guided fringe pattern normalization with optimization method is proposed based on the two orthogonal band pass filter, which includes full fringe pattern normalization and partial fringe pattern normalization. In the proposed method, energy function is designed with linear assumption for both back-ground and amplitude of the fringe pattern. Density information is estimated to guide the normalization process since better normalization performance is usually achieved in high density regions. Further, partial normalization is realized with fringe pattern separation using density information. Both simulation and experiment results vali-date the proposed method to be accurate and robust to noise. The proposed method can deal with fringe pattern with severe noise and complex intensity variation without preprocessing, thus is applicable to various types of fringe patterns.