基于混沌序列的整数小波域鲁棒水印算法

首先对图像的蓝色通道进行整数小波分解,然后将二值化后的混沌序列经扩频处理作为水印信息,将此水印信息叠加在中频系数上,最后进行整数小波逆变换重构蓝色通道,合并三通道得到水印图像。由于混沌序列对初值具有极强的敏感性,攻击者很难从一段有限长的序列推断出混沌系统的相关参数,确保水印信息的安全性。整数小波变换的优良特性使图像在嵌入适量水印信息后拥有较低的细节损失率,实现了对彩色图像的高保真水印嵌入。实验结果表明,水印信息具有很好的透明性,对有损压缩、噪声干扰等常见的水印攻击具有较强的鲁棒性。

A Robust Watermark Algorithm Based on Chaotic Sequence in LWT Domain

A watermarking algorithm for color image based on chaotic sequence in integer wavelet transform domain is proposed in this paper.Firstly,the integer wavelet decomposition of digital image is involved,and then using spread spectrum technology to make binary chaotic sequences more robust as a watermarking,chaotic sequence is added to the sub-low coefficients of the integer wavelet.Finally,watermarked image is obtained by using reverse integer wavelet transform.Because the chaotic sequence is very sensitive to the initial value,the attackers cannot deduce the whole sequence from the finite sequence then the security of watermark information is ensured.Meanwhile,this algorithm takes the advantage of the sound performance of integer wavelet transform to improve the quality of image reconstruction. Experimental results demonstrate that the proposed scheme has good robustness and imperceptibility to noise attack and common information processing operation.