台灣留學生出席國際會議補助

2009年5月5日 星期二

Automatic Extraction of Road Intersection Position, Connectivity, and Orientations from Raster Maps

論文發表人: 蔣耀毅 (南加州大學資訊科學系博士班)

http://acmgis08.cs.umn.edu/papers.html

The road network is one of the most important types of information on raster maps. In particular, the set of road intersection templates, which consists of the road intersection positions, the road connectivities, and the road orientations, represents an abstraction of the road network and is more accurate and easier to extract than the extraction of the entire road network. To extract the road intersection templates from raster maps, the thinning operator is commonly used to find the basic structure of the road lines (i.e., to extract the skeletons of the lines). However, the thinning operator produces distorted lines near line intersections, especially at the T-shaped intersections. Therefore, the extracted position of the road intersection and the road orientations are not accurate. In this paper, we utilize our previous work on automatically extracting road intersection positions to identify the road lines that intersect at the intersections and then trace the road orientations and refine the positions of the road intersections. We compare the proposed approach with the usage of the thinning operator and show that our proposed approach extracts more accurate road intersection positions and road orientations than the previous approach.

道路網絡是地圖中一項非常重要的資訊。在整個道路網絡裡面,整組道路交叉的模版(包含道路交叉的位置、道路連接數目及道路方向)不僅足以代表著這個道路網絡的幾何圖型並且自動擷取這些模版會比擷取整個道路網絡更加的容易。在自動擷取道路交叉模版的同時,細化演算法通常會用來產生一個圖素寬的道路,但是細化演算法也同時扭曲了線條的方向而導致自動擷取的道路交叉模版不準確。在這一篇文章裡,我們提供了一個新的方法來追溯地圖上的道路並且擷取準確的道路交叉模組。