The method of adjacent relation judgment and automatic direction adjustment of contour

The space relation of contour plays an important role in aspects of topographic map reading and map integration. Tree structure is highly valued as a common tool to show space relation by investigators. Studies before focused on inclusion relation of closed contours, which is complicate to build a tree structure and has a high requirement on data. Open contour occurs more and adjacent relation between contours used more widely in aspects of contour direction adjustment and form line extraction in practical production. Thus, this article tries to build a kind of loosen space adjacency level relation of contours (closed and open) and develop an integrated contour tree structure which can show this adjacent relation based on systematic analysis of the feature of contour structure, topology and property. At last, contour direction automatic adjustment model is designed based on above and the effectiveness and rationality of the model is verified through an actual data experiment.