中文摘要：

不可见性和鲁棒性是数字水印的两个基本特征。提出了一种在小波变换中频部分嵌入水印的方法。该方法从小波变换的中频部分选择待嵌入系数，并根据人类视觉系统的频率掩蔽特性对嵌入强度进行自适应调整。实验结果表明，该方法能够使水印的鲁棒性和不可见性达到较好折中，适用于灰度图像和彩色图像。

英文摘要：

Unobtrusiveness and robustness are two elementary characteristics of watermarking technology.In this paper,we propose a wavelet-based watermarking method which embeds watermark in middle frequency＇parts.By this method,wavelet coefficients are chosen from the middle frequency bands,and a well trade-off between unobtrusiveness and robustness has been achieved by adjusting the embedding intension factor according to the characteristics of HVS.The results of experiments show that the method is effective to both gray digital images and color digital images.