A new algorithm for shot noise removal in medical ultrasound images based on alpha-stable model

Ultrasonic images are generally affected by multiplicative shot noise. Shot noise filtering is thus a critical pre-processing step in medical ultrasound imagery. This paper analyses and models the coefficients of 2-D multi-resolution wavelet decomposition of logarithmically transformed images using alpha-stable distribution model. Consequently, we propose a new function that performs a non-linear operation on the data of classifying the coefficients, thus achieving a novel form of noise removal based on multi-resolution wavelet decomposition and the alpha-stable model. We compare our new technique with current shot noise reduction methods applied on actual ultrasound medical images and simulations results show that the proposed new method is more robust than the methods based on Gaussian assumption. Copyright (c) 2006 John Wiley & Sons, Ltd.