The context model describes the wavelet coefficients in a particular order with conditional probability estimates. Compression with Reversible Embedded Wavelets Ahmad Zandi, James D. Allen, Edward L. Schwartz and Martin Boliek Proceedings. Reversible wavelets are linear filters with non linear rounding which implement exact reconstruction systems with minimal precision integer arithmetic. Wavelet coefficients are encoded in a bit significance embedded order, allowing lossy compression by simply truncating the compressed data. Horizon coding is a context based coding that takes advantage of the spatial and spectral information available in the wavelet domain.
CREW has reasonable software and hardware implementations.
A method that allows for parallel compression in hardware is described. The system is generalizable to any lossless or lossy system with deterministic decompression. Prototype hardware that divides the data into multiple streams that feed parallel coders is presented. The problem of efficient transmission of multiple streams of variable-length coded data is solved by a unique coded data interleave method. Wavelet coefficients are encoded in a bit-significance embedded order, allowing lossy compression by truncating the compressed data.