两级扩展离散剪切变换数字水印算法

为了提高数字水印算法的不可见性和健壮性，将水印嵌入到最大熵子带低频大系数和最小熵子带低频小系数，并将扩展离散剪切变换的强方向敏感性引入到数字水印中。在此基础上提出了两级扩展离散剪切变换的数字水印算法。实验结果表明，新算法不仅具有很强的不可见性，加入一系列攻击后，仍能提取出水印信息。新算法具有很强的不可见性和健壮性。

Two-Stage Extended Discrete Shearlet Transform of Digital Watermarking Algorithm

In order to improve the invisibility and robustness of digital watermarking algorithm, a new wa-termark was designed and embedded into large coefficients of low frequency of maximum entropy subband and small coefficients of low frequency of minimum entropy subband. And the strong directional sensitivi-ty of extended discrete shearlet transform was introduced into digital watermarking as well. On this basis, a two-stage extended discrete shearlet transform of digital watermarking algorithm was proposed. Experi-ments show that the algorithm not only has strong invisibility, after adding a series of attacks, the water-mark can still be extracted. The algorithm has strong invisibility and robustness.