为了对视频数据进行有效保护，提出并实现了一种基于混沌序列映射灰度图像的数字水印技术。该技术首先根据视频的内容选择嵌入区域，把由混沌序列转化的平滑灰度图像嵌入到选择的区域中；然后在检测时，可通过零均值化来消除载体图像对检测的影响，且检测过程不需要原始图像。实验结果表明，这种基于视频内容和混沌的数字水印技术不仅具有良好的安全性，而且对均值滤波攻击、有损压缩攻击等均有较好的鲁棒性。

In this paper, a new watermarking technique based on chaos and video contents is proposed and implemented. A chaotic sequence which is generated by a secret key as seed is automatically transformed to two value image, and eventually converted to gray image. Selected parts of the gray image are embedded in the corresponding parts of a video frame. The selection of parts is based on the histogram of the video frame so as to embed watermark into smooth parts of the video frame. This algorithm can resist some attacks such as averaging filtering, loss compression.