一种基于数字全息及小波变换的图像水印算法

Image digital watermark algorithm based on digital holography and wavelet transform

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A rno ld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JPEG 2000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JPEG 2000有损压缩和剪切等攻击均有较好的鲁棒性。

In order to make the digital holographic watermark embedded into an original image, a new digital watermark algorithm based on digital holography and wavelet transform was presented. Since the hologram could not be destroyed, the digital hologram watermark was constitutionally robust to cropping. Furthermore arnold transform made the digital hologram watermark safer. To make the watermark invisible and robust, the disordered digital hologram watermark was processed by wavelet transform and embedded into median wavelet coefficient in the light of a zero-one matrix. The experimental results indicate that the proposed algorithm is robust to many image operations such as JPEG2000 lossy compression and image cropping.