Algorithm considering correlation of wavelet coefficients for ultrasound image denoising

Abstract

In order to suppress the speckle noise in ultrasound image,an algorithm considering the inter-scale correlation of wavelet coefficients was proposed.The algorithm used the Rayleign distribution to model the statistics of the speckle noise,and the Laplacian distribution was used to model the statistics of the wavelet coefficients of ultrasound image,and the estimation of the noise-free image through Bayesian maximum a posteriori was finally obtained.In order to preserve the details better,an inter-scale correlation factor was adopted in the calculation of the threshold,which was constructed by considering corresponding wavelet coefficients in the next scale.Experiments show that the proposed algorithm suppresses speckle noise well,while retaining the edges and details much better.