Performance comparison of different despeckled filters for ultrasound images

Abstract

Ultrasound (US) is an economical, non-ionizing, transferable, and adaptable imaging technique which have a major role in diagnosing the diseases and in image guided surgery. But due to higher frequency absorbed by tissue and skin it cannot penetrate deeply in comparison to lower frequency. So, it gives degraded quality image by echo signals and we get an inferior quality noisy image with some clinical information loss. There are various filters which despeckle the noisy US image and preserve the clinical details. In this paper, we compare the performance of four despeckle filters: Median filter, Lee Filter, Frost Filter, and Speckle Reducing Anisotropic Diffusion (SRAD) Filter in terms of peak signal to noise ratio (PSNR) and structural similarity index measure (SSIM) performance index. We have selected two parameters as: window size (3x3, 5x5, 7x7, for all iteration number 10) and number of iteration (20, 30, 40, for all window size 3x3) for performance comparison. Finally, we have seen that SRAD filter is more efficient for removing Speckle noise in comparison to other stated filters, but the performance of median filter is also good enough for speckle noise reduction.