On The Key Technology And Application Of Digital Watermarking

With the rapid development of Internet and the modern telecommunication technology, digital information security has increasingly been cared. Therefore, how now that fully utilize the Internet facilitating, can protect intellectual property effectively, be already regarded highly. As the main means protecting the intellectual property rights, digital watermarking has been studied and applied broadly now. Based on the existed works of digital watermarking, this thesis presents some effective algorithms of color image digital watermarking. The major works are as follows:1. Based on chaotic sequences, a new digital image scrambling algorithm is presented. The algorithm used Logistic mapping and Hybrid mapping to scramble the digital image at the same time. XOR operator based on Logistic mapping and Hybrid mapping is used to scramble the image, the odd-numbered lines of image XOR two-value sequences generating by the Logistic mapping and even-numbered line of image XOR two-value sequences generating by Hybrid mapping. The simulating experimentation shows that the algorithm is simple, security highly.2. A new color digital image fragile watermarking algorithm is designed based on human visual system (HVS) and chaotic sequence. By means of feature of HVS, the watermark image is self-adaptive embedded into the color image's low frequency component and middle frequency components. The algorithm has highly efficiency for using the lifting wavelet transformation (LWT). The large amount of emulation experiment indicates the algorithm has highly efficiency and security, and effect of concealing is very good.3. Based on HVS and chaotic system, a blind watermarking of color digital image algorithm is given. Making use of feature of HVS, the watermark image is embedded into the color image's low frequency component and middle frequency components by different means. The algorithm has highly security for using expanding frequency treatment,Arnold transformation and two kinds chaotic mappings to scramble the watermark image at the same time.4. A anti-attack to the shears transformation's blind watermarking algorithm of color digital image is designed based on chaotic sequences. Making use of feature of HVS, the watermark image is embedded into the color image's low frequency component and middle frequency components by different means. The algorithm has highly security due to use of two kinds chaotic mappings in scrambling the watermark image simultaneously. The large amount of emulation experiment indicates that the algorithm is a good blind watermark algorithm.5. A double digital watermarking algorithm of color image is presented based on the HVS,chaotic system and LWT transformation. The algorithm has realized the double aims of the copyright protection and the integrity authentication of image content.