一种有效的基于DCT域的数字水印算法

An effective digital watermarking algorithm in DCT domain

在DCT域中,通常将水印嵌入到AC分量上,特别是在中频系数上。近来有学者提出:图像经过DCT变换后,它的直流分量的感觉容量比交流分量大。从稳健性的角度,DC分量比AC分量更适合嵌入水印。论文旨在有实验进一步验证这一论点。实验结果表明,DC分量上嵌入水印的方法是有效的,并且具有很好的稳健性,能抵御施加在已嵌入水印的图像上的剪切、有损压缩的攻击。并与传统的离散小波变换(DWT)域的数字水印算法相比而言,其鲁棒性也是不错的。

In DCT domain,the traditional means is to hide watermarking in the AC components, especially in the middle-frequency coefficients. Recently, some scholars argue that more robustness can be achieved if watermarks are embedded in DC components since DC components have much larger perceptual capacity than any AC components. The authors aim at verifying this argument further by means of experiments. Experimental results demonstrate the strategy,which embeds watermarks in DC components, is effective and generated good robustness and images embedded watermarks can withstand attacks which exerted by tailoring ,loss compression. Comparing with the traditional digital watermarking algorithm based on discrete wavelet transform（DWT）, its robustness is not bad.