title: Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering.
abstract: This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.
authors.affiliation: King Abdullah University of Science and Technology (KAUST).
authors.forename: Ronell
authors.initials: R
authors.lastname: Sicat
authors.affiliation: University of Duisburg-Essen.
authors.forename: Jens
authors.initials: J
authors.lastname: Krüger
authors.affiliation: University of Vienna.
authors.forename: Torsten
authors.initials: T
authors.lastname: Möller
authors.affiliation: King Abdullah University of Science and Technology (KAUST).
authors.forename: Markus
authors.initials: M
authors.lastname: Hadwiger
mesh_terms: D003196:Computer Graphics; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D016011:Normal Distribution; D019047:Phantoms, Imaging; D053443:Visible Human Projects
keywords: Multi-resolution representations; large-scale volume rendering; pursuit algorithms; sparse approximation