Gobbetti, EnricoIglesias-Guitian, Jose A.Marton, Fabio2025-05-142025-05-142012Gobbetti, E., Iglesias Guitián, J.A. and Marton, F. (2012), COVRA: A compression-domain output-sensitive volume rendering architecture based on a sparse representation of voxel blocks. Computer Graphics Forum, 31: 1315-1324. https://doi.org/10.1111/j.1467-8659.2012.03124.x1467-86590167-7055http://hdl.handle.net/2183/41993This is the peer reviewed version of the article which has been published in final form at https://doi.org/10.1111/j.1467-8659.2012.03124.x.[Abstract]: 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, the volume is decomposed into a multiresolution hierarchy of bricks. Each brick is further subdivided into smaller blocks, which are compactly described by sparse linear combinations of prototype blocks stored in an overcomplete dictionary. The dictionary is learned, using limited computational and memory resources, by applying the K-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 realtime 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 demonstrated on massive static and time-varying datasets.engThis article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. © 2012 The Author(s) Computer Graphics Forum © 2012 The Eurographics Association and Blackwell Publishing Ltd.Computer graphicsPicture/Image generationThree-dimensional graphics and realismCoding and Information theoryData compaction and compressionApproximate methodsjournal articleopen access10.1111/j.1467-8659.2012.03124.x