Research On Multiple Watermarking For GIS Vector Data

Digital watermarking technology as a GIS vector data important means of copyright protection has been extensively studied. With the deepening of the application and the emergence of new needs, the robustness and applicability of single-value digital watermarking algorithms can't meet the requirements of the people gradually, so multiple digital watermarking comes into people's vision. Currently, multi-watermarking research has focused on multimedia, and studies of multiple digital watermarking for GIS vector data are in the blank state.This paper is supported by The HI-TECH Research and Development Program of China (863 Program)——Research on Key Technique for Copyright Protection of GIS Vector Data (NO.2006AA12Z222). Consideration from the current status of copyright protection and specific needs of the GIS vector data, this dissertation studies multiple digital watermarking embedding mode and strategy for GIS vector data, on the basic of research multiple digital watermarking programs of multimedia and the GIS vector data with its own characteristics. And then, a robust multi-watermarking algorithm for GIS vector data is proposed according to the research above. The major contents of studying and conclusions of this dissertation are as follows:(1) The paper studies the current typical single-value watermarking algorithms of GIS vector data. They are studied that the space domain, transform domain, zero-watermarking algorithm. These algorithms are compared and the research sums up their advantages and disadvantages.(2) Propose the four multi-watermarking embedding modes of GIS vector data: block division, domain division, frequency division, combination of the embedded watermarking and zero-watermarking. First, a detailed analysis of the characteristics of GIS vector data and research base of multiple watermarking, and then propose the four multi-watermarking embedding modes. All this provides a reference for research related to multiple digital watermarking.(3) Study the methods of multiple embedded modes. This part studies the implementation of the four multi-mode strategy and methods, and summarizes the general implementation process. In the end, a model example is designed to verify the feasibility of the strategy.(4) Design a robust multi-watermarking algorithm for GIS vector data. The dissertation develops a prototype system, and then some tests based on the system are executed. These tests include imperceptible test, data error precision analysis, and robustness test. The results show that, compared to single-value watermarking algorithms, the multi-watermarking greatly enhances the robustness, data error has also been an excellent control, and imperceptible is also good.This study makes up for the lack of research of multi-watermarking for GIS vector data. The proposed multi-embedded modes and strategy can provide a reference for other researches. It is meaningful for expanding the application range of geographical information copyright protection, and promoting healthy and rapid development of geographic information industry.