Steganography Based On Fractal Image

With the fast growing of Internet, the degree of our society's informationization becomes more and more large. As a kind of important resource, information is faced to serious security problems when being transmitted on Internet. As a solution to the issue of information security and emerging technology, information hiding has become a hotspot in the information security.Steganography is an important subdiscipline of information hiding. The current research is focused on the high-performance algorithm based on the digital image, but the selection of suitable cover image is also an important way to improve the performance of steganography. Currently the study on the theory and technique of cover image selection is also of scarcity. Natural image is most commonly used as steganography cover, but it also has limitations in the practical application. Fractal image, which is generated by computer program, is a good choice of cover image because of having many unique features different from natural image. In response to these issues, steganography based on fractal image and image complexity in the selection of cover image has been studied.The main results and contributions in this thesis are as follows.1. The effect of cover image selection for improving the performance of steganography was analyzed, the theory of image complexity in the selection of cover image was studied, and the feasibility of the idea to make selection of cover image based on image complexity was discussed.2. Based on the existing measure methods of image complexity were analyzed, it proposed a novel measure method of image complexity and tested its performance. The experimental result indicates that the method can measure the complexity of images more accurately, so it is suitable for the selection of cover image.3. A pigmentation method for complex fractal image based on fractal theory was proposed, the steganography system frame based on fractal image was designed, and the fractal image's advantages were analyzed by comparison with natural image in steganography, which lays the foundation of steganography based on fractal image.4. A steganography algorithm based on generation process of fractal images was designed and implemented. The analysis of steganography experimental results shows that the algorithm is simple and has good imperceptibility and undetectability.The research of this thesis offers necessory theory and technique for steganography based on fractal image and selection of cover image.