Motion Vector Based Video Watermarking Scheme Against Geometric Attacks
基于运动矢量的抗几何攻击视频水印方案

For many digital image and video watermarks,geometric distortions are one of the weaknesses.Even slight rotation,scaling and translation can destroy the synchronization and invalidate the detection of blind watermarks.In this paper,we present a novel video watermarking scheme that inserts a watermark intrinsically resistant to these distortions by exploiting the characteristics of the motion vector.We find that the relative relationship between characteristics of the motion vector cannot be altered with the geometric distortions easily.So the position and direction of watermark are determined according to the average values of the magnitude and direction of motion vectors.In addition,another advantage of the novel watermarking scheme is that the original video is not needed in watermark detection process.Experimental results show that the scheme is rather robust to the common geometric distortions including rotation,scaling and cutting.