一种基于正交相似变换的数字水印算法

为了提高水印的鲁棒性,提出一种基于正交相似变换的数字水印算法.首先,选取一个可逆矩阵并对其做正交变换,这个可逆矩阵可当做密钥;然后,利用该正交变换矩阵对载体进行相似变换,得到一个具有良好频谱特性的相似矩阵;最后,将置乱后的水印信息嵌入到相似矩阵中较大的非零像素值中,再重构图像.实验结果表明,该水印算法简单易行,具有较好的鲁棒性和不易感知性;与主流算法之一的DCT水印算法比较,验证了该算法的优越性.

A watermarking algorithm based on orthogonal similarity transformation

In order to improve the robustness of watermark,a novel digital watermarking algorithm based on orthogonal similarity transformation is presented.Firstly,an invertible matrix is selected and its orthogonal transformation can be used as a key;then,similarity transformation is performed using the orthogonal matrix to the vector to get a similarity matrix with good spectral characteristics;finally,the scrambling watermark message is embedded into the larger non-zero pixel values in the similarity matrix and the image is reconstructed.The experimental results show that the algorithm is simple,with better robustness and insensitiveness.Comparison with the DCT watermarking algorithm,which is one of the popular algorithms,demonstrates the superiority of the present algorithm.