一种基于DWT与DCT的扩频水印算法

变换域数字水印技术是当前的一个研究热点。本算法将水印信息与扩频序列进行扩频调制后,嵌入到载体图像的DWT与DCT中。最后利用扩频序列的自相关函数特征检测出水印信息,检测过程中不需要原始载体图像。实验结果表明,该算法嵌入水印后不易被察觉,检测出的水印效果好,对JPEG有损压缩、裁剪、噪声干扰等攻击有较强的鲁棒性。

A Spread Spectrum Watermarking Algorithm Based on DWT and DCT

In the algorithm,Use a pseudo-random noise spread sequence to spread spectrum of the watermarking and modulate the watermarking,and insert the watermarking into the DWT and DCT of the cover image By used the same pseudo-random sequence and determined its correlation with the transformed detail bands of the watermarked image,blind recovery of the embedded message is achieved.The experiment results demonstrate that the embedded watermarking is imperceptible and the proposed algorithm is robust enough to some image degradation process such as JPEG compression,cropping,noise and other attacks.