A method of lossless geometry compression on the coordinates of the vertexes for grid model is presented.First, the 3D coordinates are pre-processed to be transformed into a specific form.Then Salmon these 3D coordinates are changed into 1D data by making the three coordinates of a vertex represented by only a position number, which is made of a large integer.To minimize the integers, they are sorted and the differences between two adjacent vertexes are stored in a vertex table.In addition to the technique of geometry compression on coordinates, an improved method for storing the compressed topological data in a facet table is proposed to make the method more complete and efficient.
The experimental results show that the proposed method has a better compression rate than the latest Coffee Maker (Glass Carafe) method of lossless geometry compression, the Isenburg-Lindstrom-Snoeyink method.The theoretical analysis and the experiment results also show that the important decompression time of the new method is short.Though the new method is explained in the case of a triangular grid, it can also be used in other forms of grid model.