Research Of Watermarking Algorithm For Color Code Image

Along with the coming and rapid development of 3G era, as a new bar code technology products, the color code will be well known, and gradually integrate into people's lives. However, the subsequent security problems are also of concern, there are malicious individuals or groups may copy, disseminate or even tamper the color code without the permission of the owner, giving rise to a range of problems: copyright disputes and content authentication.Digital watermarking technology is embedding some logo information into digital products to provide copyright protection and integrality authentication, without affecting the availability of original host data.Response to the above problems and the characteristics of digital watermarking technology, the thesis, based on researching on digital watermarking technology, tries to find the right digital watermarking algorithm to solve the security issues for the color code, the major research work can be summarized as following:1. We firstly introduce the basic knowledge of the color code, such as concept, technical characteristics, technical specifications, core values and applications and so on. These knowledge lay a theoretical foundation for solving the security issues.2. We study the basic theories, attack analysis, and typical algorithms of digital watermarking, and further study the Arnold scramble, SVD, zero-watermark, chaos theory and fragile watermark. These study work provide good technical support for the design of specific algorithms.3. Combining with Arnold scrambling technology, this thesis proposes a zero watermark algorithm based on SVD for color code image. The algorithm uses the stability of SVD to construct zero-watermark.? Each block of the largest singular value can be normalized value B, then combine B and the scrambling watermark image with the XOR operation to generate zero-watermark, then store it in the Authority of the Registry to achieve color code copyright protection.?The algorithm can effectively solves the digital watermark's the contradiction between imperceptibility and robustness, and it is robust that can resist many common image attacks.4. This thesis proposes a fragile watermark algorithm based on chaotic system for color code image. The algorithm let the pixel values of R and G components of the color code, which were modulated by one chaotic system, map the initial values of another chaotic system. The watermarks obtained by iterating several times through another chaotic system were embedded into the two low bit-planes of the B components, making the watermark is invisible and good security. The algorithm can resist all kinds of tampering attacks and implement blind detection.