基于图像特征的小波域自适应水印算法

提出了一种基于图像特征的小波域自适应水印算法。该算法选用有意义二值图像为水印，把宿主图像分成互不重叠的图像块，用分数盒维数分析各块的特征，提取特征块和次特征块，对它们分别进行一级小波分解，先将水印以不同强度自适应地嵌入到特征块的小波域低频子图中，在保证隐蔽性的前提下，再次将水印以不同强度自适应地嵌入到次特征块的小波域低频子图中，该算法较好地实现了水印的隐蔽性和稳健性。为增强水印的安全性和稳健性，在嵌入前利用Arnold迭代变换将水印置乱。实验结果表明，该算法对JPEG压缩、加噪、剪切、滤波等具有较强的稳健性。

Adaptive watermarking scheme based on feature of digital image in wavelet domain

This paper presents an adaptive watermarking scheme based on the feature of digital image in wavelet domain.The watermark is binary image in this scheme.An original image is divided into non-overlapped blocks,fractional box-counting dimension is used to analyze the feature of the image blocks to extract the feature blocks and secondary feature blocks and then used one level DWT to decompose them.The different strength watermark is adaptively embedded into the low- frequency coefficients of the feature blocks,under the condition that the watermark embedded is invisible,and then is embedded into the secondary feature blocks in the same way.This scheme can get a watermarked image with perceptual invisibility and strong robustness.In order to improve the security and robustness of the watermarking scheme,the watermark is scrambled using Arnold iteration transform before embedded.Experimental results demonstrate that the watermarking scheme is strongly robust to different types of attacks such as JPEG compression,noise addition,cropping,filtering and so on.