Abstract
Ultrasound imaging is a widely used and safe medical diagnostic technique, due to its noninvasive nature, low cost, capability of forming real time imaging, and the continuing improvements in image quality. However, the usefulness of ultrasound imaging is degraded by the presence of signal dependent noise known as speckle. In this paper, we propose a new method for speckle reduction and coherence enhancement of ultrasound images based on a hybrid of total variation (TV) method and wavelet thresholding. In this model, a noisy image is decomposed into four subbands in wavelet domain. The low frequency subband contains the low frequency coefficients with less noise that can be easily eliminated using TV-based method. More edges and other detailed information like textures are contained in the other three subbands the wavelet based soft thresholding is applied on these three subbands. In the last step we use TV method to get the final denoised image since the TV is the ability of preserving edge is smoothening by wavelet thresholding. The proposed method is compared with previous methods as applied to simulated and real data using quantitative quality evaluation metrics to show the advantage of the new method.