Multipurpose watermarking for vector map protection and authentication

The rapid flourishing of GIS applications has made the copyright protection and content authentication of vector maps two important issues in the digital world. In this paper, a multipurpose watermarking scheme is proposed for the scenarios when the two requirements are needed simultaneously. In the scheme, robust watermark and fragile watermarks are embedded into the host map simultaneously. To avoid the interference between the two kinds of watermarks, robust watermark is embedded into the feature points of the objects in the map, while fragile watermarks are embedded into the nonfeature points. Due to the independence of the feature points and non-feature points, the robust watermark and fragile watermarks can be detected independently. After watermark detection, the robust watermark can be used for copyright protection, and the fragile watermarks can be used for tamper localization and characterization. The fragility of the proposed scheme is analyzed theoretically, and both the robustness and the fragility are verified by a set comprehensive experiments.