Wavelet-based contourlet packet coding using an EBCOT-like algorithm

Abstract

In this paper, an image coding algorithm based on a rate-distortion optimized wavelet-based contourlet packets (WBCP) decomposition and on a block-partitioning coding scheme which quantizes each subband separately is proposed. In this way, our algorithm naturally overcomes the difficulty in defining parent-child relationships for wavelet-based contourlet packets subbands, which exists in the zerotree based methods. The main merit of the proposed method is that the contourlet transform can provide optimally sparse representation of objects with singularities along 2 c edges and the wavelet-based contourlet packets (WBCP) can decompose the high frequency parts of the images which are not decomposed in discrete wavelet transform. The experimental results show that the proposed algorithm significantly outperforms SPIHT and JPEG2000 schemes and also surpasses recent WBCP based image coding algorithms, in terms of both PSNR and visual quality.

Direction sensitive wavelet packet for despeckling of ultrasound images

“…2 [37]. The cells 0-3 mostly corresponds to horizontal direction (−45° to +45°) and cells 4-7 corresponds to vertical direction (135° to 45°).The wedge shaped cells will have an uneven distribution of low energy components into different directional subbands [38].…”