Study On The Watermarking Technology Based On The Network

21 century is the knowledge era, the intellectual property rights protection receives the widespread attention. Along with the gradual increase of the application of the digital technique and the Internet technology, all kinds of digital media distribute and spread through the Internet, the legal dispute brought by the intellectual property rights tort question occurs frequently. The copyright protection and the information integrity assurance of the multimedia digital product has become an important question urgent need to be resolved. However, the traditional means of copyright protection and data security technology are difficult to solve these problems. The digital watermarking is developing rapidly in this background.In this paper, the digital image watermark technology based on Internet is researched. Firstly, the background and significance of watermark together with the present research conditions at home and abroad is introduced, and then the basic conception of digital watermarking technology and the system model of digital watermark is presented, after that some basic embedded arithmetic is analyzed. Secondly, the programming technology based on ASP.NET and the applications of .NET Framework GDI+ technology in the watermark is researched. At last, a visible watermarking algorithm and an invisible watermarking algorithm based on color image is designed and then realized on the Internet.The visible watermark algorithm of color image is based on spatial domain. We first convert color image from RGB to HSI and divide the image into 8×8 small pieces, and then use the original image information to obtain the embed coefficient and embed watermark on spatial domain adaptively. The visible watermark is hard to remove by common operations, which had slight impact on the color image quality and provided a good protection for original image. The size and position of watermark image all can be adjusted.The invisible watermark algorithm of color image is based on DCT domain which included embedding,detection and removal. The algorithm is carried out by modifying some coefficient according to the characteristics of Human Visual System. The detection and removal of watermark did not need original image. The invisible watermark still could be picked out even the image embed by watermark is compressed by JPEG, sharpen or cut down, which shows the invisible watermark algorithm had strong robustness.The C# programming language is used to construct an online watermark system by Visual studio 2005, then GDI + technology is used to complete algorithm in system. We could test the algorithm by accessing the Internet. The website is http://dgdz.ccee.cqu.edu.cn/watermark.In this paper, the existing invisible watermarking algorithm was improved and realized on the Internet, and the removal function was increased in invisible watermark algorithm. The two kinds of algorithm were realized in our system.