Research On Digital Watermarking Algorithms And Applications For Vector Geographic Data

Vector geographic data is an important part of the geospatial data，also is an indispensablestrategic resources in the national economy and national defense construction. It plays animportant role in the national economic construction and the foundation of people’s productingand living. Under the environment of information and network, the vector geographic data as adigital production is facing the same security issues. Moreover, due to the position and accuracyof vector geographic data, it is easier to be destroyed and will cause more extensive and seriousimpacts and losses. Under this background, it is very important to study reliable and effectivetechnologies for protecting the security of vector geographic data.Digital watermarking is in line with the applications of vector geographic data, meanwhileit inherits and carries forward the traditional security technologies. So it is playing anincreasingly important role in vector geographic data security protection. Based on theadvantages of digital watermarking, this dissertation studies digital watermarking algorithmsand applications for vector geographic data protection. The main research results are as follows:1. This dissertation studies the robust watermarking model and algorithms for vectorgeographic data. Based on the analysis of essential characteristics of transform domain robustwatermarking and the defects of existing transform domain robust watermarking algorithms onvector geographic data, this dissertation proposes a vector geographic data transform domainrobust watermarking model using data partitioning as the basis. Based on the model Thisdissertation puts forward a DFT-based anti-translation vector geographical data watermarkingalgorithm which practiced and tested the model. Based on the research of robust watermarkingand the updating problem of vector geographic data, this dissertation proposes an updatingmethod for vector geographic data based on robust watermarking.2. This dissertation studies the exact authentication based on fragile watermarking forvector geographic data.Based on the study of the vector geographic data exact authenticationtechnology and the advantage of fragile watermarking on exact authentication, this dissertationproposes a fragile watermarking algorithm for every data point. The algorithm uses vectorgeographic data feature to generate fragile watermark for every data point, and embedswatermark in the point base on the idea of quantization, so as to realize the detection of tamperand accurate position the tamper on the point. On this basis, using the feature of data point andadjacent data point together to generate fragile watermark, this dissertation proposes an exactauthentication fragile watermarking algorithm which can realize exact authentication andpositioning for all the tamper of vector geographic data. 3. This dissertation studies the selective authentication technology based semi-fragilewatermarking for vector geographic data. First, the dissertation analyses both legal and illegaldistortion in vector geographic data applications and the semi-fragile watermarking algorithmfor vector geographic data. Aiming at the case of legal distortion in data compressing, asemi-fragile watermarking algorithm for anti-compression is proposed, by using differentwatermarking methods on the feature points and non-feature points. For the cases of legaldistortion in data translation, rotation of geometric transformation, taking advantage of theconstant function that constructed by unchanged distance in geometric transformation, ansemi-fragile watermarking algorithm resisted geometric transformation is put forward. Theproposed algorithm can embed watermark in the specified location adaptively by classifying thevalue of constant function to realize the selective authentication with data translation, rotationof geometric transformation.4. This dissertation studies the compound watermarking algorithms for vector geographicdata. Based on the watermarking applications in vector geographic data, this dissertationanalyses the essential characteristics of robust watermarking and fragile watermarking. Aimingat the defects of robust watermarking when vector geographic data splicing and fusing, awatermarking algorithm based on point positioning is proposed. Using the robust watermarkingtogether with fragile watermarking to embed watermark into the data, so can eliminate theinterference of data points without watermark, makes copyright information in vectorgeographic data can be reliably detected by robust watermarking. And the updating algorithmfor vector geographic data is improved using fragile watermarking with robust watermarking,the efficiency of detecting updated data and removing watermark is improved. Also a commonvector geographical data watermarking algorithm for robust watermarking and semi-fragilewatermarking based on constant function about distance is put forward. The algorithmeffectively increases the usefulness of semi-fragile watermarking algorithm, while meeting therequirements of copyright protection and data certification for vector geographic data.5. Based on the research of robust watermarking and fragile watermarking algorithm forvector geographic data, digital watermarking prototype system for vector geographical data isconstructed using the idea of modular design. And the main function of the prototype system isintroduced.