matlab编写的对灰度图像的数字水印添加与提取程序。压缩包中有示例图片。可以添加水印，结果肉眼不易分辨出变化，不影响使用。可加入信息长度达10k字节。提取时可验证是否被修改过，如未修改，可提取隐藏信息。可标记修改位置。当图像发生旋转，缩放，少量平移时，仍能提取出强水印信息，以确保图像来源。弱水印识别率高，强水印识别率不是很高，当图像变化较小时，可以工作，变化较大时，强水印也无法提取。-matlab prepared on the gray image to add the digital watermark and extraction procedures. Compression package has sample images. Can add watermarks, the results of the changes are not easily distinguishable from the naked eye, does not affect use. Information can be added up to 10k bytes in length. Verifiable extraction has been modified, if modified, can extract hidden information. Can modify the location of tags. Occurred when the image rotation, zooming, a small amount of translation were able to extract strong watermark information, to ensure that the image source. Weak watermark high recognition rate, strong watermark is not very high recognition rate, when the image changes in small, can work, changes in large, strong watermark can not be extracted.