一种基于奇异值分解的盲水印

随着计算机和因特网技术的发展，数字水印技术开始广泛应用于数字图像、音频、视频和多媒体产品的版权保护。一种基于分块SVD的数字水印算法被提出，原始图像先进行分块SVD分解，选取每块中最大的奇异值通过量化的方法嵌入水印，在水印检测过程中不需要原始图像。同时还通过误差分析直接导出了，量化强度和信噪比的数学公式从而对选择量化强度有了理论指导。实验结论和攻击测试表明，算法对如JPEG有损压缩、中值滤波、亚抽样、低通滤波等各种的图像降级处理有很强的稳健性，同时它还对图像尺寸大小没有任何限制。

SVD Based Blind Watermarking Algorithm

A digital watermark is an invisible mark embedded in digital images, video, or audio documents, which may be used for a number of different purposes including copyright protection, authentication, and captioning. Based on block Singular Value Decomposition, a new algorithm for embedding the watermarking into the block largest singular value is proposed. And the watermarking can be detected without the original image. Meanwhile we produced a formula to estimate the PSNR with a good direction to our selection of quantity intension. Experiments and attack test show that the algorithm has good robustness on JPEG, median filter, sub-sampling, Gaussian low pass filter etc. Moreover the proposed algorithm has no limitation on the size of image.