Image Vectorization using Line Extraction and Filtering

The raster-vector conversion of remote sensing image is a very important task in the extraction and updating of linear objects in cartographic processes. In this paper we compare vectorization method and filtering method for the line extraction. Vectorization is based on constrained Delaunay triangulation, for line extraction. The constraints are provided by a preprocessing step insuring that these edges belong to line structures in the original image. The vectorization is performed using CDT and resulting triangles are grouped into polygons that make up the vector image. We use filter traces for a single road until a stopping criterion is satisfied. In this, approach, we use EKF with a special particle filter (PF) in order to regain the trace of the road beyond obstacles, as well as to find and follow different road branches after reaching to a road junction. In this paper, we have clearly discuss the advantages and disadvantages of both the algorithms over one another.