为了提高水印信息的隐蔽性和安全性，基于混沌序列的优良特性和人眼视觉系统模型，提出了一种用于图像数字水印嵌入和检测的算法。首先利用小波变换对图像进行多级分解，然后结合混沌序列的白噪声统计特性和人眼视觉对比度敏感性函数(CSF)，将混沌水印信号嵌入到从低分辨率到高分辨率的高频子带中对图像视觉影响较大的小波系数中，最后通过逆小波变换产生嵌入水印的图像。由于混沌序列对初值具有敏感性。攻击者很难从一段有限长度的序列推断出整个混沌序列的初始条件，因此可保证水印信息的安全性。同时算法结合了人眼视觉模型，有效地保护了图像的低频部分和强边缘部分。从而确保了加密图像的视觉效果。实验结果表明，嵌入水印后的图像具有很好的不可见性，同时对常见的信号处理和噪声干扰具有较好的鲁棒性。

A wavelet watermarking algorithm based on the excellent property of chaotic sequence and some characteristics of the human visual model is proposed in this paper. Firstly, the multilevel wavelet decomposition of digital image is involved, and then combined with the white noise statistical characteristics of chaotic sequence and the contrast sensitive function of human visual, chaotic sequence is added to the wavelet coefficients of the high pass bands from the low resolution to the high resolution which are important to the human visual. Finally, watermarked image is obtained by using reverse wavelet transform. Because the chaotic sequence is very sensitive to the initial value, the attackers cannot deduce the whole sequence from the finite sequence and the security of watermark information is ensured. At the same time, combined with the human visual model, our algorithm guarantees the visual impression and protects the low frequency part of image efficiently. Experimental results show that the proposed scheme has good robustness and imperceptibility to common information processing operations and noise attack.