A CONTINUITY BASED CONTOUR LINE EXTRACTION METHOD FROM RASTER TOPOGRAPHIC MAP

摘要

An automatic contour line extraction algorithm based on the continuity among the contour lines is proposed. All of the points on a contour line indicate the same elevation, the difference of elevations between every neighboring contour line is constant, and most wide contour lines have numeral array pointing out their inherent elevations. By employing the information, the shapes and elevations of contour lines can be extracted and recognized. Usefulness of the proposed algorithm is demonstrated with several practical maps.