Research On Adaptive Digital Image Watermarking Based On Chaotic Theory

Digital watermarking is a new information security technique, which is growing and developing along with the rapid progress of Internet and multimedia, it has been proposed for the copyright protection of digital multimedia. Recently, digital watermarking is becoming the most popular research interest. It is closely tied up with old information hiding and data encryption, development and fusing of them will be an indispensable security means for the development of information technology. Chaotic systems have attracted extensive interests in cryptanalysis and communications because of its noise-like, unpredictable yet deterministic orbits and sensitivity to initial condition and parameters. In this paper, we first describe the advanced research on digital watermarking technology and analyze the statistical character of several general chaotic systems, then analyze the application actuality and foreground of chaos in the field of digital watermarking. Considering the character of human visual system, a sequence of watermarking produced by chaotic system is embedded in a selected set of DCT coefficients. We exploit some new theories and methods for gray image and color image in watermark embedding strategy and extraction method, and present some valid adaptive robust watermarking algorithms. In this paper, a new public watermarking algorithm for digital images is presented based on chaotic system, and chaotic watermarking is adaptively embedded in a selected set of DCT coefficients, which achieves watermark invisibility without diminishing its robustness. Experimental results demonstrate that the watermark is robust to several signal processing techniques and geometric distortions, and its merits are as follows: Because watermark is produced by chaotic system, it has more keys and good security, even the algorithm is public, its attack is also very difficult; Because we have considered the character of human visual system, watermark is adaptive to image, which achieves watermark invisibility without diminishing its robustness and improves the anti-attack ability of watermark; Embedding strategy and extraction method are very simple, and they are suitable to color image and color image, moreover the watermark detection is blind, namely watermark extraction is performed without resorting to the original, uncorrupted image.