Title: Despeckling of medical ultrasound images by wavelet threshold optimisation

Authors: O. Saraniya; M. Ezhilarasi

Addresses: Department of Electronics and Communication Engineering, Government College of Technology, Coimbatore, India ' Department of Electronics and Communication Engineering, Government College of Technology, Coimbatore, India

Abstract: Speckle noise is the primary factor that limits the contrast resolution of diagnostic ultrasound images, thereby limiting the detection of small low-contrast lesions and making the ultrasound images generally difficult for a non-specialist to interpret. Therefore, speckle is more often considered as a dominant source of noise in ultrasound imaging and should be filtered out by a robust despeckling technique. In this paper, we compare two despeckling techniques, based on wavelet thresholding. Bayes shrinkage and genetic-algorithm-based wavelet denoising despeckling technique are implemented. Wavelet functions were studied in detail and the two algorithms were implemented using the Haar wavelet as a wavelet function. The application of this new filter on ultrasound images has shown a superior performance over the state-of-the-art wavelet-based denoising methods in terms of visual quality and structural similarity index map.

Keywords: ultrasound imaging; speckle noise; wavelet filtering; Bayes shrinkage; genetic algorithms; image despeckling; medical images; wavelet threshold optimisation; wavelet-based denoising; visual quality; structural similarity index map.

DOI: 10.1504/IJBET.2014.060985

International Journal of Biomedical Engineering and Technology, 2014 Vol.15 No.1, pp.1 - 17

Received: 02 Nov 2013
Accepted: 03 Mar 2014
Published online: 21 Oct 2014 *

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