Research On Digital Image Watermarking Technology

As development and popularity of network and digital signal processing technique, multimedia information safety looks increasingly important. As a new branch of the information hiding technique, the digital watermarking is developed on basis of meeting requirement of protecting information copyright. It refers to embedding a mark (watermark) possessing special meaning into the multimedia products according to a given algorithm so as to realize protection of this products or authentication but not effecting the use quality of this product.This paper firstly presents the basic principle and signature of the digital watermarking as well as its researching status domestic and abroad, then gives out the basic frame of the digital watermarking, describes each composition in detail, and makes classification according to different signature of the digital watermarking, which provides theoretical base for raising, realization and detection of the watermarking algorithm. In embedding watermark, it presents DWT transform domain digital watermarking embedding technique in stress, because the DWT transform domain possesses advantageous of space domain and DCT transform domain, which can be used as data compression, processing and analyzing tools, and have good use in the digital watermarking. In addition, the paper has an independent chapter to present origin of chaos, mapping of the typical chaos and its usage in the digital watermarking. Chaos sequence can be utilized to provide a large number of noncoherent signal which is similar to random because of its sensitivity to the initial value. It can be used as the watermarking signal or is very useful for watermarking encrypting.A large number of imperceptible and robustness experiments on the watermarking algorithm presented in this paper have been carried out. The simulation result shows that both of two image watermarking algorithms have perfect imperceptibility and strong robustness against the common image processing.