Research On Lossless Information Hiding Technology Of Digital Maps

With the fast development of information processing technology and network techniques, digital vector map has becoming the necessary resource being widely used in GIS, intelligent transport system, digital city, digital national defense construction and so on. Digital vector map has great economical value and strategy significance for its accurate content. And its fabricating cost is huge. On the other hand, illegal copying and stealing of digital vector map are becoming increasingly rampant. A lower level security of it will cause enterprises'losses and even bring risks to national security. As a result, the security problem has attracted our government, military and science research institution's attention. Digital watermarking technology is a common scheme to secure the copyright of digital vector map.The research on digital watermarking for digital vector map has lasted for about 20 years and many schemes have been proposed to solve some kinds of security problems of it. But these schemes have not fully considered the data characteristic of digital vector map and the particular operations on it.The two kinds of digital map, digital vector map and digital image map has been discussed in the paper. The author has studied lossless information hiding technology based on the application that can losslessly recover waterwark information, resist some attacks and trace the source maps have been proposed. The main innovative points are the following:Firstly, this paper presents a lossless zero watermarking algorithm based on wavelet fractal, which is the combination of fractal, wavelet, multiple image fractals, and wavelet fractal and so on, and the technology and implementation procedure of lossless zero watermarking algorithm based on wavelet fractal has been presented in detail. The strong robustness and lossless to vector map is proved by validity test, robustness test and IBM attack test. This model absolutely resists IBM attack and has the real value of practicability and feasibility with the third-party authentication mechanism.Secondly, spatial domain algorithm is realized by embedding watermark through changing pixel information, so its robustness is weak, its image is hurt mostly and cannot resist many kinds of attack although the implementation is simple. This paper presents the zero watermarking based on wave band superposition, of which image map is an example. What's more, the paper discusses the implementation and test of algorithm using IMG format image map as an example. This algorithm absolutely has lossless watermark embedding and watermark extracting, also has strong robustness and concealment, which is tested by anti-attack and multi-attack experiment.Finally, this paper presents independent format lossless watermarking algorithm of digital map based on digital vector map watermarking algorithm and image map watermarking algorithm because of their weak self-adaption. The algorithm combining with the advantage of cloud model and digital watermark presents generating, embedding and extracting method of cloud watermark, and do many test based on the algorithm. Cloud model has not much change although some cloud droplets is attacked because of cloud's fuzziness and randomness. The algorithm has strong robustness. In addition, the algorithm adapts to digital vector map, image map and so on, the algorithm has nothing to do with digital map's format.