A Compression Method for FEM Quadrilateral Data

This paper presents a new approach for lossless compression of engineering data, represented by quadrilaterals. The presented method works in two steps. In the first step a topology is compressed and in the second step the entropy in the remaining data is removed. The topology compression is based on ten states; three of them are automatically recognized by the compressor/decompressor and the remaining are coded by four commands. Our topology compression algorithm has been compared with Isenburg algorithm [1] and it turned out as highly competitive. During the topology compression, the geometric data and applicationspecific engineering data are also prepared for the compression. The results of compression have been compared with popular PkZip, which is frequently used for lossless compression of FEM data. As shown in the paper, we achieved considerably better results. Key-Words: FEM quadrilateral mesh, compression, topology, geometry