基于DWT和DCT双重变换的半脆弱水印算法

提出了一种基于DWT和DCT相结合的半脆弱水印算法,即从DWT域提取出图像的特征集,在Arnold置乱原始水印下生成待嵌入水印信息,通过对原始图像进行DCT变换后,按照一定准则调整并修改每块的两个中频系数来嵌入水印信息。实验结果表明,该算法对常规攻击具有较好的鲁棒性,对替换、剪切等恶意篡改能及时检测报警,而且误检率低。

Semi-fragile Watermarking Algorithm Base on DWT and DCT Dual Transform Domains

This paper proposes a semi-fragile watermarking algorithm based on combination of DWT and DCT.After the processing to the original image by using DCT,this algorithm adjusts and amends two coefficients of the middle frequency of every block to embed the binary watermarking,which is transformed from scrambled original watermarking according to the feature extracted from the original image by DWT transform.The result shows that the algorithm in this paper enjoys good robustness towards routine attack;meanwhile,it can give a timely detecting alarm when meeting vicious change such as replace and cut,and the false detecting rate is quite low.