Non-local Mean Filter for Suppression of Speckle Noise in Ultrasound Images

The speckle suppression is very important for carrying out proper clinical operation in ultrasound images. Speckle is a kind of multiplicative noise which exists inherently within the ultrasound images. Although there are many speckle noise suppression filters from the ultrasound images, it possesses certain constraints. In this paper, the Non-local Mean (NLM) filter is used to suppress speckle noise from ultrasound images. NLM filter consists of two windows that are search and similarity windows which can improve upon the limitation of many conventional filters. The simulation results of NLM filter for the values of different noise variances on ultrasound image are shown. Finally, the performance analysis is done by image quality assessment parameters like Peak Signal-to-Noise Ratio (PSNR) and Coefficient of Correlation (CoC).