Research On The Watermarking Models And Algorithms For Vector Geographic Data

Vector geographic data is one of the supportive achievements in the field of national infrastructure and geosciences research, and plays a significant role in national economy and defenses. With the development of internetwork and computer technology, the acquisition, access, dissemination and copying of vector geographic data are more and more convenient, thus an important issue that arises in the security and copyright issues of vector geographic data is becoming increasingly salient. How to use feasible technology to secure the copyright protection of vector geographic data is a major social need which is urgently needed to resolve.Digital watermarking technology is a new information security technology, and can provide a feasible and practical solution for the copyright protection for the vector geographic data. The characteristics of vector geographic data watermark technology are analyzed, and the digital watermarking models and algorithms for vector geographic data are studied based on wavelet transform, collection mappings, constant function, and mathematical statistics and so on. The main results are as follows:(1) Based on the own characteristics of the vector geographic data, the characteristics of the digital watermarking technology for vector geographic data is analyzed; this paper classify the watermarking attack of vector geographic data through the analysis of the impacts of different watermarking attack; the design strategies of watermarking algorithm against different attacks are discussed.(2) Based on the characteristics of vector geographic data, three different watermarking algorithms for vector geographic data are proposed. A vector geographic data watermarking algorithm resisted data compression is proposed by embedding watermark into feature points; a high-fidelity vector geographic data watermarking algorithm is proposed through embedding watermark in the moving redundant points that inserting into line segment; a watermarking algorithm for vector geographic data is proposed based on the wavelet transform and the segment-embedding thinking.(3) Through the analysis of the key technology of watermark embedding and extracting, a watermarking model for vector geographic data is proposed based on set mappings thought, the model can be used to guide the design and implementation of vector geographical data watermarking algorithm. Based on the proposed model and non-mean watermark generation, a watermarking algorithm adapted small data for vector geographic data is proposed, the proposed algorithm can resist data adding and deleting attacks.(4) A watermarking algorithm for vector geographical data resisted data translation is proposed based on the symmetry characteristics of quantitative rules and the match detection method, the proposed algorithm can resist data adding and deleting attacks and also can resist compound attacks composed of data translation ,data adding and data deleting attacks. Based on invariant function has non-denatured for some of the transform, a invariant function under translation, rotation, scale transformation is derived, then a watermarking algorithm resist geometrical transform is proposed, which can resist data adding, data deleting, data translation, data rotation, data scaling and complex attacks composited of above attacks.(5) The characteristics of splicing attack is analyzed, basic strategies resist splicing attack are discussed. By visualizing the single point detecting result, a interactive watermark detection algorithm resists splicing attack is proposed; in order to achieve automation and batch watermark detection, a watermark detection based on method of meshing-detection-merging which also resist splicing attack is proposed. The proposed algorithms can detect watermark exactly from the watermark data which suffer different types of data splicing attacks.(6) A robust watermark detection algorithm is proposed, which solves the problem of setting detection threshold, experimental results show that the proposed algorithm is adapted to vector geographical data. A self-detection watermarking algorithm for vector geographical data is proposed, which can be used to judge whether there is watermark in the vector geographical data.(7) The impact of watermarking to the usability of watermark vector geographical data is analyzed, considering the usability of watermark-data, four types of spatial constraint rules are established, and a watermark embedding strategy is constructed based on the space constraint rules.(8) Based on the research of watermarking models and algorithms, a three-level framework for watermarking system is designed, digital watermarking prototype system for vector geographical data is constructed, and the main function of the digital watermarking system for vector geographical data is introduced.