• Soumya Kulkarni

I n this paper we present a contourlet based lossy image compression method and texture representation for medical ultrasound thyroid images. Texture representation of ultrasound (US) images is currently considered a major issue in medical image analysis. In this algorithm we use contourlet transform for image decomposition. Then, we apply a thresholding process on the coefficients before quantization. We select the threshold due to coefficients occurrence in the contourlet domain. This algorithm has the ability of simultaneous speckle reduction using another thresholding. Due to this time saving ability, the algorithm can be used in online image transmission systems. We implement our method on ultrasound images. Results proved that our proposed method has acceptable performance and good performance over common compression methods such as wavelet based SPIHT in the case of PSNR. Texture representation of ultrasound (US) images is currently considered a major issue in medical image analysis. This paper also investigates the texture representation of thyroid tissue via features based on the Contourlet Transform (CT) using different types of filter banks. A variety of statistical texture features based on CT coefficients, have been considered through a selection schema. The Sequential Float Feature Selection (SFFS) algorithm with a k-NN classifier has been applied in order to investigate the most representative set of CT features. For the experimental evaluation a set of normal and nodular ultrasound thyroid textures have been utilized. The maximum classification accuracy was 93%, showing that CT based texture features can be successfully applied for the representation of different types of texture in US thyroid images.

contourlet transform, ultrasound images, feature extraction, thyroid, feature selection.

"Compression and Texture representation of Ultrasound thyroid images by Contourlet transform", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.2, Issue 6, page no.1740-1745, June-2015, Available :http://www.jetir.org/papers/JETIR1506011.pdf

"Compression and Texture representation of Ultrasound thyroid images by Contourlet transform", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.2, Issue 6, page no. pp1740-1745, June-2015, Available at : http://www.jetir.org/papers/JETIR1506011.pdf