小波域数字图像水印改进算法及其性能分析

提出一种结合随机加密的小波域图像水印算法．利用小波变换对原始载体数字图像进行多分辨率分解；利用由密钥产生的伪随机序列对水印图像进行随机置乱．根据原始图像的相同分辨率、不同方向、相同空间位置的小波细节子带系数的大小关系，将经过随机置乱处理的包含版权信息的二值水印图像嵌入到载体图像．提出一种水印检测算法，不需要使用任何与原始载体图像相关的信息，实现了“盲检”．实验证明，提出的水印方案具有非常好的不可见性；对于大量的攻击具有较好的鲁棒性；使用两道密钥具有很好的安全性．

Digital Watermarking Based on Wavelet Transform with Random Sequence Scrambling

A new digital watermarking scheme based on wavelet transform and random sequence is proposed. The source carrier image is first decomposed by wavelet transform. The binary watermarking image with copyright information is scrambled by a pseudo-random sequence generated from the secret key. Then the binary watermarking image is embedded into carrier image. The watermarking image extraction process doesn't require any knowledge of the source carrier image. The experimental results show that the watermarking image is invisible and robust against a number of attacks. The watermarking information is safe because using two secret keys.