一种基于NCG和SVD的数字视频水印算法

Digital Video Watermarking Algorithms Based on NCG and SVD

目前关于奇异值分解水印算法很多,大部分不能实现水印盲提取,并且有关视频水印的SVD算法也不多。基于视频水印的这种现实,现提出了一种基于NCG、SVD的数字视频水印算法。首先计算每帧的NCG值,用NCG值对视频帧进行分类,选择具有NCG阈值特征的帧。然后对每帧实施分块SVD,在SVD奇异值矩阵中取第二个元素组成新的矩阵。然后对新矩阵实施DCT变换,更改其中的一对DCT中频系数而嵌入水印。仿真实验表明,该算法具有较好的透明性,能实现水印盲检测,可抵抗常见的各种攻击,如裁剪、高斯、泊声噪声等。

There are a lot of algorithms about singular value decomposiytion watermarking in nowadays but most of them can＇ t carry out blindly extraction. Besides, there are not much SVD algorithms about video watermarking. A video digital watermarking algorithm base on DCT, SVD, NCG is provided. In accordance with NCG, the video frame into categories is divided. Choose the frame with NCG feature, conducts SVD blocking, the second element in the singular values after SVD to make a new matrix is selected. A DCT transform change to it is made. One pair of the medium frequency coefficient before embedding the indicates that this algorithms has much transparency watermarking into the matrix modified. The imitated experiment and can blindly extract watermarks and resist various common attacks such as cropping, Gaussian, Poisson noise