A novel multiscale nonlinear diffusion method for ultrasonic speckle reduction

A novel approach for ultrasonic speckle reduction based on a multiscale nonlinear diffusion (MND) is presented. In this approach, speckle is removed by nonlinear adaptive filtering of the individual bandpass levels of the multiscale Laplacian pyramid. The nonlinear adaptive filtering is implemented by a nonlinear diffusion process. The proposed MND method can reduce speckle noise significantly while preserving sharp image details. Moreover, selective amplification of image details is possible. The superiority of the proposed MND over the conventional nonlinear diffusion and a state-of-the-art wavelet-based speckle reduction technique is demonstrated by applying them on synthetic and real ultrasound B-mode images.