Abstract: This paper presents an adaptive watermarking algorithm based on FCM wavelet domain.A host image is decomposed with two level wavelet transform，and the binary image is adaptively embedded according to the texture sub-blocks，these sub-blocks are obtained on the wavelet domain middle-frequency coefficients by applying FCM based on the human visual system.This algorithm can get a watermarked image with perceptual invisibility and strong robustness.In order to improve the security of the watermarking algorithm，the watermark is scrambled before embedded.Experimental results show that the algorithm is strongly robust for the common image processing techniques such as JPEG compression，cropping，noise addition，low-pass and median filtering and so on.

Key words: wavelet transform, Fuzzy C-Means（FCM）, image watermarking

摘要： 提出一种基于FCM 的小波域自适应水印算法。该算法对宿主图像进行二层小波分解，根据人类视觉系统的掩蔽性对小波域的中频系数进行分类并结合FCM，自适应地将二值水印图像嵌入到图像的纹理子块中，能较好地实现水印的鲁棒性和隐蔽性;在嵌入前将水印置乱，增强了水印的安全性。实验结果表明，该算法对JPEG压缩、剪切、加噪、滤波等常规攻击具有较强的鲁棒性。

关键词: 小波变换, 模糊聚类, 图像水印