Acompression-domain output-sensitivevolume rendering architecturebased on a sparse representation ofvoxel blocks

We present a novel multiresolution compression-domain GPU volume rendering architecture designed for interactive local and networked exploration of rectilinear scalar volumes on commodity platforms. In our approach, thevolumeisdecomposedintoamultiresolutionhierarchyofbricks.Eachbrickisfurthersubdividedintosmaller blocks,whicharecompactlydescribedbysparselinearcombinationsofprototypeblocksstoredinanovercomplete dictionary.Thedictionaryislearned,usinglimitedcomputationalandmemoryresources,byapplyingtheK-SVD algorithm to a re-weighted non-uniformly sampled subset of the input volume, harnessing the recently introduced method of coresets. The result is a scalable high quality coding scheme, which allows very large volumes to be compressed off-line and then decompressed on-demand during real-time GPU-accelerated rendering. Volumetric information can be maintained in compressed format through all the rendering pipeline. In order to efficiently support high quality filtering and shading, a specialized real-time renderer closely coordinates decompression with rendering, combining at each frame images produced by raycasting selectively decompressed portions of the current view- and transfer-function-dependent working set. The quality and performance of our approach is demonstratedon massivestaticandtime-varying datasets. Categories and Subject Descriptors (according to ACM CCS): Computer Graphics [I.3.3]: Picture/Image Generation—Computer Graphics [I.3.7]: Three-dimensional graphics and realism—Coding and Information Theory[E.4]:Data compaction andcompression—Compression(Coding) [I.4.2]:Approximate methods— 1