Speckle suppression by adaptive nonlinear filtering

Using a good statistical model of speckle formation is important in designing an adaptive filter for speckle reduction in ultrasound B-scan images. Most clinical ultrasound imaging systems use a nonlinear logarithmic function to reduce the dynamic range of the input echo signal and emphasize objects with weak backscatter. The statistic of log-compressed images for Nakagami distribution was derived (Ghofrani et al. 2001) and in this paper we use the results for designing an adaptive nonlinear filter in speckle reduction. We processed two original ultrasound images of kidney and liver to demonstrate the efficiency of the designed filter.