An Efficient Algorithm for Large-Scale Volume Data Compression and Its Application in Seismic Data Processing

The size of large scale volume data sets to be visualized by direct volume rendering on programmable graphics hardware is often limited by the amount of available graphics memory,as it will lead to frequently data transfer between memory and GPU. To get rid of this limitation,an efficient large-scale volume data compression algorithm based on VQ is presented. The volume data set is first divided into smaller regular blocks and each block is classified according to whether its average gradient value is zero or not. Then,blocks with non-zero gradient values are re-organized into a three-level hierarchical representation. To the top two levels,a splitting scheme based on principal component analysis is applied to find their initial codebooks. LBG algorithm is then conducted for codebook refinement and quantization. Blocks in the lowest level and those with zero average gradient values are quantized with fixed number of bits. Experimental results show that,in addition to good fidelity,the presented algorithm can obtain more than 50 times compression rate with fast decoding speed.