基于小波变换和人类视觉系统的稳健水印算法

Robust watermarking algorithm using wavelet transform and HVS

提出了一种基于小波和人类视觉系统的稳健数字水印算法,首先将宿主图像进行小波分解,根据人类视觉系统求出重要小波系数,然后将灰度水印图像通过Arnold变换进行置乱,最后将置乱后的水印信息加入到宿主图像的重要小波系数中.提取水印信号需使用置乱密钥.置乱密钥的使用提高了置乱算法的安全性,使水印的安全依赖于密钥.在小波域中利用人类视觉系统使嵌入水印的图像具有较好的鲁棒性.数值实验和理论分析表明,该算法针对各种攻击具有很好的鲁棒性和更高的安全性.

A novel wavelet-based watermarking scheme for copyright protection of digital image is presented. Host image was decomposed through wavelet transform. The significant coefficients of wavelet were selected according to the human visual system （HVS） characteristics. With this method, watermark was scrambled through Arnold transform before it was embedded. The usefulness of keys and privacy of modification to frequency coefficients enhance the security of watermark information. Experimental results show that the quality of the watermarked image is good and there is strong resistance against general image processing. Furthermore, the extracted watermark can still be easily identified after being attacked by different ways.