BIDIRECTIONAL VERTEX PREDICTING METHOD

摘要

PROBLEM TO BE SOLVED: To encode a vertex by such a method as to attain a new function by sequencing vertexes in tree structure having at least two hierarchies and encoding a predictive error by an entropy encoding method which is bidirectionally predicted from the two vertexes of upper hierarchies. SOLUTION: Shape information is obtained by a shape extracting module 11, sent to a vertex selecting module 12 to select a point on an outline as the vertex of polygonal approximation of a shape and sent to a vertex encoding module 13. The module 13 consists of a vertex sequencing module 14, a bidirectional vertex predicting module 15 and an area limited entropy encoding module 16. The module 13 sequences the vertexes into tree structure by the module 14. Each hierachy of tree structure is bidirectionally predicted from hierachy higher than it by a module 15. The module 16 encodes a predictive error.