一种基于QR分解的DWT域水印算法

提出一种基于QR分解的小波域图像水印算法,是将水印信息矩阵做QR分解并嵌入到做离散小波变换后的载体图像的两个特殊的区域.首先将原始图像进行归一化处理后做离散小波变换,并计算出嵌入区域的嵌入强度;再将水印按照密钥进行置乱;然后再对置乱后的信息做正交分解,得到两个正交矩阵;分别将这两个正交矩阵使用加性规则自适应地嵌入到小波变换域的低频和对角方向上;最后小波逆变换得到含水印的图像.实验结果证明,本算法具有较好的鲁棒性、安全性和不可见性,特别是抗几何攻击效果尤其明显.

A Watermarking Algorithm Based on OR-Decomposition in DWT Domain

A QR-based watermarking algorithm is developed in the wavelet domain for images.The algorithm is based on discrete wavelet transform and embeds the watermarking two matrics from QR-decomposition of watermarking image.Firstly,the host image,which is in one treatment,is transformed into discrete wavelet transform domain,and two scale factor is calculated according to scale version of the host image;Secondly,according to the first key,the watermarking image is transformed for scrambling;Then,QR-decomposition is implemented for two matrices;and these two matrices are separately embedded into low and diagonal directions of DWT domain adaptive according to adder rules with the two scale factors;finally,the marked image is agained through inversing discrete wavelet transform.Experimental results show that our scheme makes a better beautiful tradeoff between imperceptibility and robustness,and achieves securit,particularly,the effect of anti geometric attack is evident.