Wyniki wyszukiwania - BazTech

1

Automatic seed point selection in ultrasound echography images of breast using texture features

Selvan S., Shenbaga Devi S.

Biocybernetics and Biomedical Engineering

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2015

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Vol. 35, no. 3

157--168

EN

Automatic segmentation of breast lesions in 2D ultrasound B-scan images via active contours, require a seed point to be selected inside the breast lesion. The grey levels on an ultrasound image of the breast show intensity information. The fat tissue is hypo echoic relative to the surrounding glandular tissue. The glandular parenchyma tissue usually appears homogeneously echogenic as compared with fat lobules. Simple cysts are anechoic. Malignant solid masses are usually heterogeneous, hypo echoic and tend to look intensely black compared to surrounding isoechoic fat. Benign solid masses tend to appear on ultrasound with intense and uniform hyper echogenicity. Texture features represent changes in grey level intensities. This paper proposes a method that can automatically identify a seed point based on texture features and allow automatic contour initialization for level set segmentation. This seed point plotted on an US B-scan image is mapped on to its corresponding elastogram pair. The proposed approach is applied to 199 ultrasound B-scan images of which 52 are benign solid masses, 84 malignant solid masses and 63 simple and complex cysts. The seed point obtained using this approach is mapped to its corresponding elastogram pair in 62 US B-scan and US elastography image pairs. Quantitative experiment results show that our proposed approach can successfully find proper seed points based on texture values, in ultrasound B-scan images and therefore in elastography images, with an overall accuracy of 86.93%. This approach is effective and makes segmentation of breast lesions computationally easier, more accurate and fast.

2

Investigations on vehicles guided by updated road and maps

Rajinigirinath D., Selvan S.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 9

297-301

EN

The scope of this paper is to analyze performance of automatic vehicles during data dissemination with the realtime updated road information into the maps followed by the vehicle moments. Both modeling and development of the additional subsystems needed such as communications, reference/sensor systems and mobility are considered. The primary reason is that for solving both traffic congestion and safety problems to save time and fuel. The proposed location based algorithm analyses the features of complete automation of the driving function with suitably equipped road facilities.

PL

W artykule analizowano właściwości pojazdu automatycznego otrzymujące informacje o drodze w czasie rzeczywistym. Rozważano system przesyłu danych, system czujników oraz parametry ruchu przy kryterium oszczędności czasu i paliwa.

3

Wavelet-based modeling of singular values for image texture classification

Ramakrishnan S., Selvan S.

Machine Graphics and Vision

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2006

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Vol. 15, No. 2

211-225

EN

A new algorithm based on the wavelet packet transform is proposed for the classification of image textures. Energy matrices are formed from subband coefficients of the wavelet packet transform. Singular value decomposition is then employed on the energy matrices. The probability density function of singular values is modeled as exponential distribution, and the model parameter is estimated using the maximum likelihood estimation technique. The model parameter, one for each subband, is used to form the feature vector. Classification is carried out using the Kullback-Leibler Distance (KLD). Performance of the algorithm is compared with model-based and feature-based methods in terms of the signal-to-noise ratio and the classification rate. Experimental results prove that the proposed algorithm achieves better classification rate under noisy environment.