DIGITAL WATERMARKING FOR COPYRIGHT PROTECTION AND AUTHENTICATION

Abstract

With the rapid growth of internet technology in recent years, people can distribute and exchange digital media more quickly and easily than ever: The ease with which digital data can be duplicated and distributed over the internet has raised many concerns about copyright infringement. In many situations, multimedia data (images, music, movies, etc.) are illegally circulated, thus violating intellectual property rights. Digital watermarking recently emerged as a possible solution for copyright protection and authentication. The work presented in this thesis is concerned with developing robust watermarking algorithms and assess their appropriateness for certain problems. Our aim is to evaluate the proposed schemes using application scenarios of copyright protection, tamper detection and authentication. In our work, we have emphasized on the robustness and security of the algorithms. Robustness is the property to resist against attacks intending to remove the watermark. The results of this thesis show that the proposed watermarking algorithms are extremely robust against all types of distortions, especially against geometric distortions. On the other hand, security has to do with the ability of the watermarking systems to properly conceal the information that must be kept secret, such as the secret keys and the embedded messages. In this process we have developed some watermarking algorithms, whose security also lies on secret keys. This thesis comprises of seven chapters. First chapter gives a brief introduction about digital watermarking. In the next five chapters, the proposed algorithms are explained and evaluated. Finally we close the thesis with conclusions and some future research directions.