由于二维DCT变换是对数字图像矩阵而言的，所以对于RGB位图不能进行DCT变换我在这里先将它转换成灰度图像再把水印嵌入到灰度图像中来进行基于DCT变换的图像水印研究。-As the two-dimensional DCT transform on the digital image matrix is concerned, therefore, for the RGB bitmap should not be DCT Transform I first convert it into gray image and then watermark is embedded into gray-scale images for image based on the DCT Transform watermarking research.