Embedding Point Selection Algorithm For Road Network Data Fingerprinting Considering Map Scale Transformation

In recent years, the rapidly development of Web GIS makes the transmission of map dataquick and convenient, and it also makes map data web publishing, map data cop ying anddistribution between departments and social individuals become widespread behavior intransactions, which put forward a higher demand for geospatial data copyright protection.Vector map data is the key element of national spatial data infrastructure in GIS industry,military and defense sectors. How to confirm the owner, legal/illegal users and illegalcommunicators of the data at the same time during the process of vector map data distributionand transmission is an urgent issue in geographic information science.In order to prevent the illegal reproduction and dissemination of the vector map data, it isnecessary to study efficient map data security strategy. On the technical aspects of geographicinformation science, map data security strategy means how to identify the owners, legitimateusers, illegal users and communicators of the transmitted data. Digital watermarking andpassword cannot recognize the illegal copying and illegal disseminators of the data, however,digital fingerprinting technology can achieve this goal perfectly. So the solution to theproblem of vector map data security depends on the digital fingerprinting technology.Therefore, this paper is intended to do the following studies by selecting the digitalfingerprinting embedding technology of vector map data of road network for the productionand application of vector map.(1)To study the topology structure of the vector map data of road network and analyzethe automatic generalization results of road network. Road network is divided into the mainroads and branch roads. In the process of map generalization (by large scale to small scale),the effect of the points on the main roads is small (typically kept) and that on the branch roadsis big (usually be deleted). Obviously, if a point on the branch roads is used as the digitalfingerprinting information embedding, the fingerprinting information embedded in it will belost when some points on the branch roads are deleted in map scale transformation, and thiswill cause the lack of fingerprinting information. Therefore, considering the influence of mapgeneralization, fingerprinting information should be embedded in the retained point in orderto guarantee the missing of fingerprinting information to the greatest degree. However, thefingerprinting information cannot be embedded in all retained points, and it should beembedded in the special points on the main and branch roads in order to improve theefficiency of embedding algorithm,(2)To propose an efficient method for the selection of road network fingerprintinginformation embedding point. To research what point in the road network is the key point (thepoint which is not easy to change with the scale, because digital fingerprinting embedded in these points is able to make fingerprinting resist on the map scale transformation as much aspossible) during the process of scale transformation, and how to quickly and effectively selectthe key point in which fingerprinting information is embedded. And this plays a certain role inpromoting the security protection of vector map road network data.