提出了一个基于频域块分类的DCT域自适应水印算法。为了实现自适应，将原始图象分块并利用视觉掩蔽特性对图象块进行分类。根据分类的结果，不同强度的水印分量被嵌入到图图象块的DCT低频系数中，实验结果表明，应用所提出的算法实现的水印对常见图象处理和噪声干扰具有良好的稳健性。

In this paper,an adaptive image watermarking algorithm in DCT domain based on the block classification is proposed.By exploiting the visual masking features of HVS,the algorithm splits the original image into blocks and classifies these blocks.Watermark components with different strength are inserted into some low-frequency coefficients adaptively according to the clsaaification.The experimental results demonstrate that the watermarks generated with the proposed algorithm are invisible and robust against noise and commonly used image processing techniques.