基于分块离散小波变换的图像信息隐藏与盲提取算法

摘要

提出了一种在小波域中图像信息隐藏与盲提取算法．该算法首先对载体图像进行分块两层离散小波变换，找到每块第二级分解子带中的最大值即最重要小波系数，然后根据小波特征树的对应关系将其在第一级分解子带中的对应区域作为嵌入区域，在该区域嵌入由秘密信息生成的伪随机序列．提取过程中，同样按照小波系数对应关系寻找到嵌入区域并判断其与伪随机序列的相关性即可解密，不需要提供原始图像．实验结果表明，该算法能实现二值图像的嵌入与盲提取，且提取出的图像质量较好并具备一定的抗攻击能力，尤其对于剪切攻击的鲁棒性较好．%In this paper, we propose a blind watermarking algorithm based on block discrete wavelet transform. The watermark is scrambled by Arnold and two pseudo random sequences are generated first, and then according to the wavelet tree structure, the significant wavelet coefficients in a block are found and quantized by pseudo random sequence. During the extraction, the quantized coefficients can be found without the original image, then the correlation between them and the pseudo random sequences are calculated to estimate the watermark bits. Moreover, in this method all high-frequency subimages are used to provide better robustness. The performance of the proposed watermarking is robust to several attacks, especially quite effective against image cropping attack.