Density Guided Fringe Pattern Normalization with Optimization

Fringe pattern normalization is an essential preprocessing step for the data analysis of the optical interferometric 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 background 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 validate 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.