Enhanced Wavelet Block Tree Based Image Coding Algorithm

A novel scheme,"WBTC (wavelet block tree coder) algorithm" that allows a substantial reduction in the storage size of an image is proposed in this work. The coding algorithm is based on the spatial orientation tree (SOT). The major feature of this WBTC algorithm is that it fuses both zero-tree and zero-block algorithm. The key feature of wavelet decomposition is its energy clustering property in space and frequency. When the discrete wavelet transform (DWT) is applied, image is represented by set of wavelet co-efficients. Then the WBTC algorithm is applied and significance is tested at each level. It will partition the image into significant and insignificant blocks. Significant block is quad partitioned into four sub blocks until all the significant co-efficients are found. This procedure is repeated to the next resolution. Performance of the proposed method is compared with the other state-of-art coding algorithms including JPEG2000, SPIHT for many images. Simulation results show that the proposed algorithm has a better coding efficiency over the other coders at very low bit rates.