Robust Spread Spectrum Based Digital Video Watermarking Scheme in Frequency Domain

There is an explosion of data exchange on the Internet and the extensive use of digital media. Consequently, digital data owners can quickly and massively transfer multimedia documents through the Internet. It has aroused intense interest in multimedia security and multimedia copyright protection, and this has become a critical issue in the modern digital era. The problem is severe in case of digital video as several copies of duplicate videos can be made on optical disks even with cheap commodity computers. This results in recording, editing and replication of multimedia contents, thereby providing revenue losses. Digital watermarking technique is the process of embedding noise-tolerant signal in the carrier signal. This dissertation focuses on the embedding of watermark bits into the video frames. A given video sample is spilt into frames for watermark embedding. A frame is first transformed into frequency domain using Discrete Fourier Transform. A watermark, modulated with PN sequence is transformed and added to the Fourier coefficients and then the inverse is obtained of modified Fourier Coefficients to get watermarked frame. This process is repeated to the entire length of video to get watermarked video. The video watermarking algorithm proposed is robust against the attacks of frame dropping, averaging and statistical analysis. Peak Signal to Noise Ratio (PSNR) is used as the quality metric for watermarking scheme. Mathematical techniques are presented and simulation are carried out using MATLAB.