Journal d'informatique et de biologie des systèmes

Medical Image Application by Hybrid Transform Coding Scheme

Abstract

Ali Rostam, Hawar Hawar, Mhsin Mhamad, Barzan Ahmad and Halo Qad

Efficient compression of images using hybrid schemes has become the spotlight for developers in recent times. Hybrid compression techniques (DWT and DCT) are the basis of the proposed compression scheme presented in this paper. The aim here is to achieve higher compression threshold while maintaining the quality of the reconstructed image, attempting to achieve this by using different compression levels on wavelet coefficients of the DWT (HH and LL) bands, in the time when (HL and LH) bands are undergoing DCT transform. According to the type of transformation, adaptive quantization of the retained coefficient is performed. Lastly the quantization indices are encoded using entropy coding (variable shift coding). Results of our trails indicate using hybrid DWT-DCT algorithm significantly improves coding performance.