Wavelet Domain Image Watermarking Algorithm

With the development of communication, computer and Internet technology, humans' lives have been changed dramatically. Based on the technology of computer and network, the multimedia information exchanges provide a convenient way for using and spreading of digital produces. This make digital products have more advantages than traditional products, and digital multimedia has become main means of information communication. While one can acquire a wide range of multimedia data through the Internet, various problems (copyright violation, illegal copying, easy forging, etc.) arises naturally that seriously harm the benefit of the author or the copyright owner. How to protect multimedia data from violation has become an important issue in information security field. As a main application of information hiding technique to multimedia copyright protection, the digital watermarking technique, which embeds an invisible signal (watermark) to the original multimedia data (image, audio, and video), has been proposed as a viable solution for the copyright protection and authentication of multimedia data in a networked environment since it makes it possible to identify the author, owner, distributor or authorized consumer of multimedia data. So it has drawn extensive attention in recent years and has become the most popular research interest.Digital watermarking is still in his infancy, and many problems remain yet to be solved. This paper addresses research of image digital watermarking algorithm. The main contributions are summarized as follows:Firstly, this paper introduces the research background, then reviews history of digital watermarking and sums up the current developing condition, and point out some problems of digital watermarking.In this paper, the author first makes an overall review on the digital watermarking techniques including the definition, characteristics, main application domains , basic features of digital watermarking. Then the general frame of digital watermarking is given. Finally, this paper introduces the attacks and countermeasures.As the processing of watermarking-scrambling is taken into account, image-scrambling algorithms such as Arnold transformation, Rubik Cube Transformation are introduced and simulated.The process of development, basic definition, multi-resolution analysis of wavelet, Mallat algorithm and its application in the image processing are introduced. An effective digital watermarking algorithm based on the Arnold permutation method is proposed in this paper. In our algorithm, the watermark is embedded to the low frequency coefficients of the L-deep wavelet domain. The experimental results demonstrated that the embedded watermark is not only invisible, but also robust against the attacks of the noise addition, filtering and so on.This paper proposes an algorithm based on singular value decomposition algorithms in wavelet domain. Embedding strategy and extraction method are very simple. The experimental results demonstrated that the watermark is fairly robust to several signal processing techniques.