Graphical display of three-dimensional surfaces is the most effective means of conveying our everyday world in a computer application. Such programs are often executed remotely through a computer network. Transmission of the large amount of data required for an accurate rendering requires substantial channel bandwidth. Lossless compression algorithms for mesh data can therefore improve the performance of these computer programs. A mesh is generally represented by a list of vertices and a list of faces, each of which is a list of vertex indices. The list of faces, referred to as the connectivity data because it shows how the vertices are connected to each other, constitutes the bulk of the mesh data. In this dissertation, I propose a new reversible compression algorithm for connectivity data of a mesh.; In the new method, the connectivity of a three-dimensional object is snapped onto a two-dimensional grid before being encoded. After encoding, a lossless compression algorithm, such as Huffman coding, is used to further compress the symbol stream. The capability of this new method is demonstrated with three-dimensional planar triangle meshes. For a planar triangle, meshes containing V vertices, our technique provides between 1.4V and 3.0V bits for the connectivity cost, compared to 6Vlog2V bits required without compression. As our approach does not depend on the vertex locations, we may separately compress the vertex data with any vertex-encoding method currently available.
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机译:三维表面的图形显示是在计算机应用程序中传达我们日常生活的最有效方法。此类程序通常通过计算机网络远程执行。精确渲染所需的大量数据的传输需要大量的信道带宽。因此,网格数据的无损压缩算法可以提高这些计算机程序的性能。网格通常由顶点列表和面列表表示,每个面列表都是顶点索引列表。面列表称为连通性数据,因为它显示了顶点之间的连接方式,构成了网格数据的主体。本文针对网格的连通性数据提出了一种新的可逆压缩算法。在新方法中,三维对象的连通性在进行编码之前会先捕捉到二维网格上。编码后,使用无损压缩算法(例如霍夫曼编码)进一步压缩符号流。三维平面三角形网格展示了这种新方法的功能。对于包含 V italic>顶点的平面三角形,我们的技术提供了 1.4V italic>和 3.0V italic>位之间的连接成本,而6 < italic> V italic> log 2 sub> V italic>位,无需压缩。由于我们的方法不依赖于顶点位置,因此我们可以使用当前可用的任何顶点编码方法分别压缩顶点数据。
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