Study On Robustness Of Digital Watermarking Techniques Based On Communication Model

With the rapid growth of Internet usage, digital multimedia works becomes more and more easy to be acquired, copied and transmitted. Consequently, the protection of copyright of these works turns to be an important issue. Digital watermarking is the technique to embed some digital signals called digital watermark into the digital multimedia content to protect its copyright. The embedded watermark is usually imperceptive. However, a detector can be used to extract it or verify its presence or absence. This paper focuses on the improvement of robustness of image digital watermarking technique. For this purpose, a new scheme is proposed, which embeds multiple watermarks into the same multimedia content. Some preliminaries of watermarking technique are presented firstly, which include basic conception, applications, properties, models of digital watermarking technique. And then, some conventional ideas to improve the robustness are introduced. Next, multiple watermarking technique is discussed, and is used to improve the robustness. Finally, some conclusions are drawn, and merits and demerits of the work are commented, and the tasks for further investigation are also given.This paper focuses on three aspects. The first one is to exploit new schemes to improve the robustness of digital watermarking based on conventional ideas. According to the principles and methods proposed by other papers, three new watermarking systems, namely, System Repeat, System Anti-noise and System Anti-crop are proposed. The second one focuses on how to improve the robustness of the watermarking technique by employing the multiple watermarks technique, which is a new way leading to the improvement of robustness. A new watermarking system named System Combine, is implemented, and a new idea of embedding multiple watermarks are proposed too. This is the foremost part of the paper. Except for the two aspects above, many other watermarking systems are also implemented, all of which are proposed by other researchers. Corresponding experiments on robustness have been carried out to verify the validity of each system.Theoretic analysis and computer simulation show that the proposed watermarking systems do improve their robustness effectively.