@article{KaelbererPolthierReitebuchetal.2005, author = {K{\"a}lberer, Felix and Polthier, Konrad and Reitebuch, Ulrich and Wardetzky, Max}, title = {Free Lence - Coding with free valences}, series = {Computer Graphics Forum}, volume = {24}, journal = {Computer Graphics Forum}, number = {Issue 3}, doi = {10.1111/j.1467-8659.2005.00872.x}, pages = {469 -- 478}, year = {2005}, language = {en} } @article{TycowiczKaelbererPolthier, author = {Tycowicz, Christoph von and K{\"a}lberer, Felix and Polthier, Konrad}, title = {Context-based Coding of Adaptive Multiresolution Meshes}, series = {Computer Graphics Forum}, volume = {30}, journal = {Computer Graphics Forum}, number = {8}, doi = {10.1111/j.1467-8659.2011.01972.x}, pages = {2231 -- 2245}, abstract = {Multiresolution meshes provide an efficient and structured representation of geometric objects. To increase the mesh resolution only at vital parts of the object, adaptive refinement is widely used. We propose a lossless compression scheme for these adaptive structures that exploits the parent-child relationships inherent to the mesh hierarchy. We use the rules that correspond to the adaptive refinement scheme and store bits only where some freedom of choice is left, leading to compact codes that are free of redundancy. Moreover, we extend the coder to sequences of meshes with varying refinement. The connectivity compression ratio of our method exceeds that of state-of-the-art coders by a factor of 2 to 7. For efficient compression of vertex positions we adapt popular wavelet-based coding schemes to the adaptive triangular and quadrangular cases to demonstrate the compatibility with our method. Akin to state-of-the-art coders, we use a zerotree to encode the resulting coefficients. Using improved context modeling we enhanced the zerotree compression, cutting the overall geometry data rate by 7\% below those of the successful Progressive Geometry Compression. More importantly, by exploiting the existing refinement structure we achieve compression factors that are 4 times greater than those of coders which can handle irregular meshes.}, language = {en} } @inproceedings{KaelbererTycowiczPolthier, author = {K{\"a}lberer, Felix and Tycowicz, Christoph von and Polthier, Konrad}, title = {Lossless Compression of Adaptive Multiresolution Meshes}, series = {XXII Brazilian Symposium on Computer Graphics and Image Processing}, booktitle = {XXII Brazilian Symposium on Computer Graphics and Image Processing}, doi = {10.1109/SIBGRAPI.2009.53}, pages = {80 -- 87}, abstract = {We present a novel coder for lossless compression of adaptive multiresolution meshes that exploits their special hierarchical structure. The heart of our method is a new progressive connectivity coder that can be combined with leading geometry encoding techniques. The compressor uses the parent/child relationships inherent to the hierarchical mesh. We use the rules that accord to the refinement scheme and store bits only where it leaves freedom of choice, leading to compact codes that are free of redundancy. To illustrate our scheme we chose the widespread red-green refinement, but the underlying concepts can be directly transferred to other adaptive refinement schemes as well. The compression ratio of our method exceeds that of state-of-the-art coders by a factor of 2 to 3 on most of our benchmark models.}, language = {en} } @misc{KaelbererPolthierReitebuchetal., author = {K{\"a}lberer, Felix and Polthier, Konrad and Reitebuch, Ulrich and Wardetzky, Max}, title = {Compressing Triangle Meshes using Geometric Infomation}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-8016}, number = {04-26}, abstract = {We introduce FreeLence, a lossless single-rate connectivity compression algorithm for triangle surface meshes. Based upon a geometry-driven traversal scheme we present two novel and simple concepts: free-valence connectivity encoding and entropy coding based on geometric context. Together these techniques yield significantly smaller rates for connectivity compression than current state of the art approaches - valence-based algorithms and Angle- Analyzer, with an average of \$36\\%\$ improvement over the former and an average of \$18\\%\$ over the latter on benchmark 3D models, combined with the ability to well adapt to the regularity of meshes. We also prove that our algorithm exhibits a smaller worst case entropy for a class of "'well-behaved"' triangle meshes than valence-driven connectivity encoding approaches.}, language = {en} }