一种基于数字全息及小波变换的图像水印算法

为了实现在原始图像中嵌入数字全息水印，提出了一种以数字全息和离散小波变换为基础的数字水印算法。由于数字全息图具有不可撕毁性，使得数字全息水印本身就具有良好的抗剪切能力。数字全息图通过Arnold变换置乱，增加了安全性。为了满足水印的不可感知性和提高抗JPEG2000有损压缩能力，将置乱后的数字全息图水印经过小波变换后，按照一个随机0、1矩阵再结合人类视觉系统特性自适应地嵌入到中频小波系数中。实验表明，该水印算法对JPEG2000有损压缩和剪切等攻击均有较好的鲁棒性。

Image digital watermark algorithm based on digital holography and wavelet transform

In o rder to make the dig ital holo graphic watermark embedded into an or ig inal imag e, a new digital w atermark alg orithm based on dig ital holo graphy and w avelet t ransform w as presented. Since the hologram could not be dest ro yed, the digital ho logr am w atermark was const itut ional ly robust to cr opping . Furthermore arnold t ransform made the dig ital holo gram w atermark safer. To make the w atermark invisible and ro bust , the disor dered dig ital holog ram w atermark w as processed by w avelet t ransform and embedded into median wavelet coef ficient in the light of a zero-one matr ix . T he ex perimental result s indicate that the proposed algor ithm is robust to many imag e o perat io ns such as JPEG2000 lossy compression and image cr opping .