基于小波提升的公有水印技术

结合小波提升和人的视觉系统(HVS)等特点,提出一种基于9/7双正交小波提升的图像数字水印算法。采用伪随机序列对水印图像加密调制;对原始图像进行小波提升的多分辨率分解,考虑HVS对水印嵌入高低频子带感知不同性和鲁棒差异性,依据高频子带系数构建嵌入水印的标志定位矩阵,通过该矩阵实现高低频子带嵌入水印的位置映射,设置合适阈值,在逼近子带上进行自适应水印的嵌入。最后通过标志定位矩阵和逼近子带的位置映射,成功地从逼近子带里提取公有水印并进行伪随机序列解密。实验表明该数字水印系统具有很好的不可感知性和双重安全性,且具有抵抗JPEG、JPEG000压缩攻击的鲁棒性。

A public image watermarking technique based on wavelet lifting

A Public image watermarking technique based on wavelet lifting transform and Human Visual System (HVS) is proposed in this paper. Firstly, the watermark sequence is encrypted by pseud - number sequence. Then we design a labeling position matrix of embedding watermark using the high frequency matrix of image multi - resolution. Digital watermark is embedded into the low frequency domain by the labeling position matrix which maps the low frequency matrix of the image multi - resolution. Finally, the watermarking is completely pick - upped from the law frequency domain without the original image. The experimental results show that the novel algorithm is feasible in the copyright protection.