基于双变换的图像数字水印算法

Image Digital Watermarking Algorithm Based on Double Transforms

为了更好地嵌入水印,在基于DWT基础上,对载体和水印图像同时进行小波变换.即将载体和水印图像同时采用小波基函数先进行变换,然后在他们相应的变换域中进行水印嵌入,不同于以往的嵌入对策.该算法不仅增强了水印的不可见性和鲁棒性,也扩大了水印的嵌入量,而且计算简单,水印采用二值图像且是盲半脆弱水印.最后,与最新提出的SWT作了比较,结果表明,DWT的优点是不容忽视的.

In order to embed the watermarking much better, based on DWT, wavelet transform is applied not only in carrier, but also in watermarking images at the same time. Wavelet basis function is simultaneity applied in carrier and watermarking images at first, and then watermarking in their corresponding transform domains embedeled. Being different from the past embedding policies, this algorithm is not only invisible to the image but also enlarging the watermarking quantity. In addition, it can be calculated easily, the watermarking being binary image and also blind semi-fragile watermarking. Finally, it gives a comparison with SWT the latest proposed, and the experiments indicate that the advantages of DWT can＇ t be ignored.