Image Watermarking Algorithm

Following the sharply development of Internet, it is more and more easy to get some digital multi-media information. However, it also causes some problems, such as copyright protection and information encryption, which become more urgency day by day. Therefore, many scholars are attracted by the multi-media information security problem. In this thesis, the author studies one of its branch - digital watermarking of images. First, some basic conceptions, specialties and application domains of it are introduced. Second, the pretreatment of digital watermarking data is discussed one by one, and their shortcomings and excellence are also pointed out. Third, many kinds of embedding technology of digital watermarking data is analyzed carefully, and their powers to resist some kinds of attacks arc introduced. Then, two new embedding technologies about gray digital watermarking are suggested, based on DWT and DCT separately. The author implements them and analyzes their results and performances. The experimental results demonstrate that the second has a better power to resist attack of robust. Finally, the author gives out some suggests on the possible research directions in the future.