Combined denoising filter for fringe pattern in electronic speckle shearing pattern interferometry

摘要

We propose an effective image denoising filter that combines an improved spin filter (ISF) and wave atoms thresholding (WA) to remove the noise of fringe patterns in electronic speckle shearing pattern interfer-ometry. The WA is first employed to denoise the fringe to save the processing time, and then the ISF is further used to remove noise of the denoised image using WA to obtain a better denoising performance. The performance of our proposed approach is evaluated by using both numerically simulated and experimental fringes. At the same time, three figures of merit for denoised fringes are also calculated to quantify the performance of the combined denoising filter. The denoised results produced by ISF, WA, and bilateral filtering are compared. The comparisons show that our proposed method can effectively remove noise and an improvement of 12 s in processing time and 0.3 in speckle index value is obtained with respect to ISF.