General construction of transform-domain filters, filtering methods for electronic speckle pattern interferometry, and comparative analyses.

In this paper, we first present a general method for the construction of transform-domain filters for the removal of speckle noise in electronic speckle pattern interferometry (ESPI) wrapped phase patterns. Then we review the construction of previously published representative transform-domain filters, including the Fourier transform (FT), the wavelet transform, windowed Fourier filtering, and the localized FT filter. Furthermore, we fully evaluate the performance of the four filters via a variety of test cases and a comparable mean square error. Lastly, we also propose three new transform-domain filters for the removal of speckle noise in ESPI based on the general method. The three new methods are developed by selecting the input image function and filter function with better performance. The filtering results of the three proposed methods have been demonstrated via comparisons with four previously published filters.