An Efficient Image Codec based on Backward Coding of Wavelet Trees

Backward coding of wavelet trees (BCWT) is a new approach for encoding images in the wavelet domain. This new approach starts coding from the lowest level and goes backward by building a map of maximum quantization levels of descendants. BCWT eliminates several major bottlenecks of existing wavelet-tree-based codecs, namely tree-scanning, bitplane coding and dynamic lists management. It also encodes and decodes up to eight times faster than SPIHT without sacrificing PSNR and provides desirable features such as low complexity and low memory usage