CRUSH: a comparative lossless compression package

The NASA Goddard Space Flight Center has developed a lossless compression package called “CRUSH” for facilitating the comparison of several lossless compression algorithms by compression ratio and computational efficiency. The latest release of the CRUSH package contains seven variants of four algorithms that are appropriate for broad classes of data or textual files. Included are a Witten-Neal-Cleary (WNC) arithmetic coding algorithm, WNC coding paired with an adaptive dependence source model, two sliding window Lempel-Ziv variants, the Rice algorithm, and the contextual model of the lossless JPEG combined with WNC arithmetic coding. The CRUSH package can be built and run on VAX/VMS systems, and a wide range of UNIX or UNIX-like systems. The authors describe the algorithms contained in the CRUSH package, and report on study using the CRUSH package for evaluating lossless compression approaches for the Goddard Version 0 DAAC. Finally, they give comparative results for selected NASA data sets