基于混合变换域的数字水印算法

提出了一种基于二维离散小波变换(DWT)和离散余弦变换(DCT)的混合变换域数字水印算法。通过小波变换得到载体图像的高频和低频系数,将低频系数作为一个子图像;再将二值水印图像置乱并编码,在子图像的离散余弦变换得到的系数中嵌入水印。该方法在水印检测和提取过程中都不需要原始图像。实验表明该方法水印隐藏性好,鲁棒性较好,抵抗放缩和局部攻击有很好的表现。

Digital Watermarking Algorithm Based on Hybrid Transform Domain

A new digital watermarking algorithm of hybrid transform domain based on DWT and DCT is proposed.The wavelet coefficient of the original image is got through wavelet transform,and the low frequency coefficient is seen as a subimage.Then the binary watermark image is permuted and coded,the watermark is embedded into the coefficient which got from the DCT of the subimage.The proposed algorithm can detect and extract the watermark without the help of the original image.Experimental results show that this new algorithm is imperceptive and robust,and has a good performance against the scaling and the local attack.