Comparative analysis of interferogram noise filtration using wavelet transform and spin filtering algorithms

摘要

The aim of this paper is to analyze 2D fringe pattern denoising performed by two chosen methods based on quasi1D twoarm spin filter and 2D discrete wavelet transform (DWT) signal decomposition and thresholding. The ultimate aim of this comparison is to estimate which algorithm is better suited for highaccuracy measurements by phase shifting interferom etry (PSI) with the phase step evaluation using the lattice site approach. The spin filtering method proposed by Yu et al. (1994) was designed to minimize possible fringe blur and distortion. The 2D DWT also presents such features due to a lossless nature of the signal wavelet decomposition. To compare both methods, a special 2D histogram introduced by Gutman and Weber (1998) is used to evaluate intensity errors introduced by each of the presented algorithms.