Abstract: In order to provide more watermarks and to minimize the distortion of the watermarked image, a technique using the combinational spatial and DWT domains is presented in this paper. We splits the watermarkimage into two parts and make them random permutations respectively,which makes the degree of protection double .We embed one part in the spatial domain of the host image and the other in the DWT domain of the image which has contained the first part already.We embed the watermarking in the DWT with different intensities. Experimental results indicate that the technique has higher security,larger capacity and less distortion..It insures the robustness and imperceptibility of watermarking.

Key words: DWT, digital watermarking, image permutation

摘要： 为了在不破坏原始图像质量的情况下,嵌入更多的水印,即较好的解决水印算法的不可见性和鲁棒性这对矛盾,本文提出了一种基于时域和小波域的组合算法.先将水印分成两部分,分别进行置乱,使安全性加倍.然后将一部分嵌入原始图像的时域中,再将此含一部分水印的图像进行小波变换,把水印以不同强度自适应的嵌入其中.实验结果表明,该算法不但具有很高的安全性,而且在增加了水印的容量的前提下,图像的质量降低很小,很好的统一了水印算法的不可见性和鲁棒性。

关键词: 离散小波变换, 数字水印, 图像置乱