【摘要】 空间域随机置乱和锐化滤波是基本的图像处理方法。在某些数字图像水印系统中,水印嵌入前对原始图像做随机置乱预处理,水印提取前对水印图像做锐化滤波预处理,可以有效地改善视觉效果,提升水印检测的准确率。本文在Barni半盲水印算法中验证了该方法的有效性。此外,本文设计了一个新的DCT域水印算法,并对该方法做了进一步验证。算法中,将水印嵌入到图像相邻块的DCT系数差值上。实验证明,该算法在保持良好视觉效果的前提下对常见图像处理具有较强的鲁棒性。更多还原

【Abstract】 Random permutation and sharpening are basic methods of image processing.In some digital image watermarking systems,if the original image is pre-processed with random permutation before embedding and the watermarked image is pre-processed with sharpening before detection,the performance of watermarking can be improved,which means the images can look better,or the veracity rate of detection is higher.In this article,this scheme is validated in Barni’s semi-blind watermarking system.In addition,a new watermarking scheme is designed in which both permutation and sharpening are used to insure the performance.In this scheme,watermarking is embedded into the difference of neighboring blocks’ DCT coefficients.The experimental results show that this scheme is robust to various image processing.更多还原