An approach of vectorization of RS classified map

Based on the theory of vectorization of raster data,a method of vectorization of RS classified map has been put forward.First of all,the polygon is divided into simple polygons and complex polygons which are processed separately,then turn left algorithm is used to handle non-inclusion relation of the polygon and an algorithm to determine the relationship of polygon in polygon is used to identify the relationship of polygon in polygon(including situation with sharing-boundary islands).The method can better solve the unsatisfactory vectorization problem of sharing-boundary islands,and after vectorization of the sharing-boundary islands a more complete topology can be formed.After using this approach to vectorization,vectorgraph is basically able to meet the actual needs.