METHOD FOR REPRESENTING THREE-DIMENSIONAL GEOMETRIC DATA, METHOD AND DEVICE FOR COMPRESSION/EXPANSION AND RECORDING MEDIUM OF PROGRAM FOR REALIZING THE COMPRESSING/EXPANDING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for compressing/expanding three-dimensional geometric data arranged in a three-dimensional space without losing the data. SOLUTION: The coordinates values of the three-dimensional geometric data are divided into a plurality of groups (S11), folding vector information that regulates the relations of the coordinates values among the divided groups is derived (S12), and whether or not the relation between the derived folding vector information and the original coordinates values is appropriate is decided (S13). A data compressing method consisting of respective steps having a function for replacing (S14) the coordinates values among the groups decided to be appropriate with the folding vector information instead of eliminating the coordinate values and an expanding method for restoring the coordinates values according to the procedures of the reverse sequence of the compressing method are used.