Investigations on edge preservation and smoothening of frequency domain filters for speckle removal in breast ultrasound images. (2016)

• Record Type: Journal Article
• Authors: Singh, Bikesh kumar; Verma, Kesari; Thoke, A.S.
• Is Part Of: International journal of biomedical engineering and technology. Volume 20:Number 2(2016)
• Page Start: 97
• Page End: 115
• Publication Date: 2016
• Subjects: image filtering -- speckle noise -- frequency domain filters -- breast images -- ultrasound imaging -- edge preservation -- visual assessment -- smoothing -- image quality -- visual perception -- wavelet filters -- homomorphic filters -- image processing; Biomedical engineering -- Periodicals; 610.28
• Languages: English
• ISSNs: 1752-6418

Abstract

Spatial domain methods for reducing speckle noise are more efficient but their performance is highly sensitive to size, shape of window and threshold used during filtering process. Hence frequency domain filtering is more appropriate if suitable and straightforward kernel or threshold cannot be found in the spatial domain. Unfortunately, they result in over smoothening, loss of edges and sharp details. In this paper various frequency domain techniques for the suppression of speckle noise are compiled and investigated. Further, they were evaluated using suitable image quality metrics and visual perception evaluation by two experts. Experiments were conducted on 37 breast ultrasound images. The results of comparative study using various image quality metrics show that wavelet filter with first level decomposition and eliminated HH band [Wav(HH/1)] outperformed others. On the other hand, homomorphic filter with wavelet filter function Wav(HH/1) outperformed others in visual assessment carried out by two experts.