Based On The Digital Image Of The Chaotic Sequence Spread Spectrum Watermarking Algorithm

With the popularity of network and the advance of multimedia technology, it is possible to create, replicate, transmit, and distribute digital content in an effortless way. It is an urgent task to effectively protect the intellectual copyright of multimedia. However the traditional encryption systems have been limited to use in this aspect. As the multimedia data are once decrypted, there is no way to detect its copyright and track its possible unauthorized dissemination. Digital watermarking has been proposed as a new information hiding technique for the information security, intellectual property and certification enforcement of digital media, it is a new method to protect copyright by embedding the secret information into the open multimedia data, and has become a very active research hotspot in academic fields. The thesis focuses on the applications of chaotic sequences in the digital image spread spectrum watermarking.Firstly, the background, significance, present situation, basic concepts, algorithmic block diagram and application areas of the digital watermarking are introduced; then the paper analyzes the algorithms of spread spectrum watermarking, and introduces the spread spectrum theory and evaluation criterion. The results of experiments demonstrate: this digital watermarking has good robustness; the m and Gold spread spectrum sequences is not the best.Secondly, the thesis describes the concepts and typical features of chaos, and gives a new algorithm of spread spectrum watermarking based on the chaotic sequences. In the watermarking project, chaotic sequence is presented to make use of its properties, such as sensitivity on their initial conditions and good statistic characters, significance watermarking is realized dual-encryption with chaotic sequences of the same private key, this improves the security of watermarking. At first, binary watermarking image is encrypted by the chaotic sequences, and due to the characteristic of HVS, the watermarking is embedded into the lower frequency band...