A Novel Digital Watermarking Algorithm Based On Symmetry And The Phase Angle Of Motion Vector

With the development of information technology and computer networks, digital video and pictures, which takes a rich amount of information, are widely disseminated in networks. That has introduced great challenge for the authenticity and copyright protection of the multimedia. Digital watermark as a new copyright protection technology, embeds watermark into the multimedia and extracts the watermark information to identify the copyright. It attracts much more attention due to its significant role.This paper aims to find a better solution to the copyright protection in multimedia based on the development of technology of today's multimedia and the outstanding achievements for the current digital image processing. The paper proposes new watermark algorithms both in water-flipped images and h.264-encoded videos, facing the shortcomings and deficiencies of current watermark methods and the problem in the application of digital watermarking process. For the water-flipped images, the paper use the Mirror-reflection Invariant Feature Transform (MIFT-SIFT) to choose the position of the watermark, and design the watermarking method in the frequency domain, so that the algorithm is resistant to geometric attacks and other digital signal attacks while minimizing the influence to the original image; For the most popular h.264 video, the various aspect of the encoding process are deeply studied. An improved phase angle based video watermarking algorithm is proposed during the Inter-encoding process, and evaluated on standard video sequences, which effectively eliminates the distortion introduced by embedding watermarks, and keeps a low bitrate while preserving high quality of the video.