向数据多媒体(如图像、声音、视频信号等)中添加某些数字信息以达到文件真伪鉴别、版权保护等功能。嵌入的水印信息隐藏于宿主文件中，不影响原始文件的可观性和完整性。(Some digital information is added to the data multimedia (such as image, sound, video signal and so on) to achieve the function of authenticity identification, copyright protection and so on. The embedded watermark information is hidden in the host file, which does not affect the observability and integrity of the original file.)