Image Watermarking Technology Based On Multi-Scale Analysis

With the rapid development of computer technology and network communication technology, digital information security has increasingly been cared. Its background is that data-exchange and data-transfer has been more convenient. Digital watermarking is a efficiency means on resolve digital multimedia information security. This thesis presents some effective algorithms of image digital watermarking. The major works are as follows:1. A new image scrambling algorithm was proposed based on chaotic sequence and bit exchange. According to the pixel location, the algorithm changed the image pixel values by using XOR operation in different Logistic chaotic sequence and the binary sequence of pixel value. Without iteration, the algorithm used the self-relativity if image. Experimental data and results show that the algorithm can achieve more effective image scrambling compared with the traditional algorithm. The algorithm has good performance in resisting the salt pepper and cutting attack. Compared with the iterative type's scrambling methods, it has higher too.2. Based on Curvelet and chaotic sequences, a digital image fragile watermarking algorithm is presented. The algorithm scrambling watermarking image used Logistic chaotic sequence and bit exchange and used Curvelet transform the initial image and watermarking image. According to the average coefficient, the algorithm is self-adjust the basic embed intension. The algorithm has highly efficiency for using the Wrapping. The large amount of emulation experiment indicates the algorithm has highly efficiency and security. And effect of concealing is very good.3. Based Curvelet, a blind watermarking of color digital image algorithm is given. The algorithm use Arnold chaotic system to scrambling watermarking image, and based HVS use Curvelet transformed initial image's Q component, blocked the low frequency component and SVD. The watermarking is embedded into the most SVD. The large amount of emulation experiment indicates that the algorithm is good blind watermark algorithm.