Development of a map vectorization method involving a shape reforming process

摘要

Described is an automatic map vectorization method to obtain geographical data from paper maps, for DB-systems using map information, such as GIS. The method consists of component separation, and skeleton vectorization. To obtain accurate vector data, several special segmentation techniques and a new skeleton vectorization technique is introduced in the method. The segmentation techniques are used to extract line drawings, character symbols, and other components, such as painted objects, from the original map image. The new skeleton vectorization technique involves a shape reforming process to reform vector shape distortion caused by raster-to-vector conversion. The process is based on the energy minimization principle. The process has an advantage in regard to reducing the various kinds of distortions, compared with using conventional processes. Through map input experiments with the method, it was proved that the method an obtain accurate vector data, compared with conventional techniques.