Research On Adaptive Digital Image Watermarking Based On Chaotic Theory

Currenly,the rapid development of computer networks represented by Internet,"E-Government","E-Commerce"and the extensive application of information systems,is causing profound changes in social and economic.However,the acquiration of digital multimedia information is becoming more easily, meanwhile, it is also more easily suffer the attacks such as illegal copying, fabricating tampering, infringement etc.The conventional safety precautions which based on the cryptology did not have the ability equal to their ambition. In order to protect the digital product itself security as well as the owner's benefits, people put forward the digital watermarking technique.Digital watermarking is a technology which with the precondition of having no affection to the quality of the digital product, embedding the secret information into the digital product which can't be seen to attain the protection of digital product. Generally, it possesses three basic characters of imperceptibility, robustness and security.Digital watermarking technique, which embeds special inforriiation into digital products, is a new method for copyright protection. There are three main transform domain methods: the DFT, the discrete cosine transform and the discrete wavelet transform. The paper will focus on the wavelet domain, the major research works in this article are as follows:Firstly, the paper makes a comprehensive introduction about the algorithms of digital watermarking which based on wavelet transform. At first the background, the development and the algorithm's actuality of digital watermarking is introduced, dissertate the digital watermarking about the basic concept and character, generic model, typical algorithms, classification, application domain, attack analysis and evaluation of performance are also introduced.Secondly, elaborating the theory of chaos and its application .Making a simple introduction about chaotic technical and the logistic chaos model based on the two-dimensional chaos mapping watermark image.Doing careful research on digital watermark algorithm based on chaotic model. A image watermarking algorithm based on two-dimension chaos encryption is proposed, Use the two dimension logistic chaotic map to generate the watermark. The feature of the image is analyzed by using fractional box-counting dimension joining human vision system. Scrambled watermark is two times embedded into the low-frequency in wavelet domain when embedded watermarking.This scheme can get a watermarked image with perceptual invisibility and strong robustness. The extracted watermark is the average of two extracted watermarks.Result indicates that this algorithm has obvious advantages,compared with not been encrypted two-dimensional logistic chaotic system pre watermarking algorithm,it is strongly robust to different types of attacks such as JPEG compression, noise addition, cropping, filtering and so on.Finally, we review the entire work, and make the expectation of the direction for the future research of watermarking.