Wavelets applied to lossless compression and progressive transmission of floating point data in 3-D curvilinear grids

A method of lossless compression using wavelets is presented that enables progressive transmission of computational fluid dynamics (CFD) data in PLOT3D format. The floating point data is first converted to double-precision floating point format to maintain adequate precision throughout the transform process. It is then transformed using Haar wavelets-four times in two spatial dimensions, twice in the third spatial dimension, and twice in time for a total compression factor of 64 times. The double precision format will maintain enough precision during the transform to keep the process lossless. Next, the transformed data is compressed using Huffman coding and transmitted progressively using spectral selection. This allows most of the information to be transmitted in the first pass. Details are transmitted in later passes which ultimately provide for lossless reconstruction of the original data.