实现数字水印技术，将重要信息隐藏在图片中，供对方提取识别。-Digital watermarking technology to the important information hidden in the picture for the identification of the other extracts.

用matlab实现图像离散余弦变换（DCT）信息隐藏和信息提取-Implementation using matlab image discrete cosine transform (DCT) to hide information and extract information