Linear filtering of 2-D wavelet coefficients for denoising ultrasound medical images

► We address the problem of denoising ultrasound medical images affected by speckle. ► We propose and analyze the performance of a method based on 2-D wavelet transform. ► We evaluate the denoising performance without/with filtering of wavelet coefficients. ► We evaluate the denoising performance at different levels of speckle noise. ► We compare the results with other popular denoising techniques (median and Wiener). The paper presents a novel denoising method for ultrasound medical images, whose quality is degraded by the peculiar phenomenon of speckle noise. The method is constructed step-by-step on the basis of recent research on the topic, and consists in Gaussian filtering of proper wavelet coefficients of the image, corresponding to vertical and diagonal details. A comparison with other filtering techniques for ultrasound imaging, i.e. Wiener and median filter, is presented. The obtained results, combined with those reported in independent research, demonstrate that the proposed denoising scheme has very good performance and is very promising for actual medical application.