数字图像水印的分析与实现
摘要：针对现在数字媒体版权保护的问题，本设计在数字图像小波变换的基础上，在原始图像上嵌入水印图像。嵌入的图像水印即能表征作品的所有权。数字水印是利用数字作品中普遍存在的冗余数据与随机性把版权信息嵌入在数字作品本身中，从而起到保护数字产品版权或者完整性的1种技术。
具体实现过程：先对原始图像（即需版权保护的作品）和水印图像做3层小波变换，然后将水印与原始图像的3层小波系数相加，为了水印图像的不可见，运算时将水印系数乘以1个嵌入因子。水印的提取过程与嵌入过程恰好相反，即对嵌有水印的图像作品和原始图像做3层小波变换，然后将带水印图像的小波系数与原始图像的`小波系数相减，结果除以嵌入因子，即得水印图像。
该方法属于在图像变换域上的水印的嵌入法，要得到鲁棒性好的水印，又要使作品的版权验证简单明了，需要对水印的嵌入方式做精心设计。
关键词：小波变换；水印；鲁棒性
Analysis and realization of digital image watermark
Abstract：In response to the issue of copyright protection about the media, the images wavelet transform in the design is the basis of the original images embedded watermarks in images. Embedded images watermarks that can scale works ownership. Digital watermarks widespread is the use of digital works in the random nature of the redundant data and information embedded in the digital copyright works themselves, thus protecting a copyright or completeness of a digital product technology.
Concrete realization process : first the raw images (that is, the need to protect copyright works) and Watermark images do three-tier wavelet transform, then Watermark images with the original three-tier wavelet transform calculated to Watermark images not visible, computers will be multiplied by a factor of watermarks embedded factors. Watermark extraction process with embedded processes to the contrary, that there are watermarks on the images inlay works and the original three-tier wavelet images do change, and then bring Watermark images wavelet coefficient with the original images wavelet factor subtract that result divided by embedded factors that may Watermark images.
The methods of transformation where the watermarks in images with embedded France to be good watermarks robustness, but also enable copyright certification simple, the need for the embedded watermarks way so carefully designed.
Keywords: wavelet transform; watermark; robustness
注释：不含源代码