Abstract
With the development of digital technology and popularization of internet, digital information could be duplicated and spread easily. On the other hand, because anyone can copy, falsify and even forge any data they obtained, the digital content owners and creators suffer serious piracy. It is evident that copyright protection of digital content has become one of the most important subjects in current. To solve this problem, two principal technologies are developed. One is digital watermarking and the other is cryptography. Digital watermarking technique allows anyone to access the protected data, but only the valid owner can extract the information from the host data to authenticate the ownership by watermarking technique when the dispute about the copyright of data happened. On the other hand, cryptography systems permit only valid key holders to access encrypted data. However, data is no longer protected once it is decrypted. Therefore, the digital content could be watermarked and then encrypted by means of cryptography to improve the information security. Based on intellectual property attention in information era, how to protect the personal ownership is more and more important and necessary. Hence, in this thesis we address a digital video watermarking technique based on DCT approach to insert the message which possesses high transparency and slight distortion. The watermark is mainly embedded into the uncompressed domain by adjusting the correlation between DCT coefficients, and the watermark can be extracted without using the original video information. The proposed system consists of embedding process and extracting process. Both of them are adopted a pseudo 3D DCT to achieve this scheme. In this way, our approach can reduce the computational complexity and computational time efficiently. The secret embedding key is employed to assist in extracting watermark to enhance the system security. In this way, the embedded watermark can not be extracted even though the algorithm is broken. Furthermore, the proposed system provides a good elasticity of design by using the adjustable parameters. Finally, we compare our proposed system with anterior methods. The experimental results illustrate that the proposed scheme possessed higher transparency and robustness to against various, e.g. filtering, noise, luminance modifications, especially compression, than other methods.