基于DCT的彩色图像数字水印算法

实现一种在彩色载体图像中嵌入彩色水印图像的算法。在嵌入时，先将载体图像分成与水印图像大小相同的块；然后，在DCT变换域中，将水印图像R、G、B层的变换系数嵌入到载体图像每一块对应层的中低频系数中。在提取时，先通过DCT反变换从带水印图像的每一块中提取出水印图像，再计算这些水印图像的平均值从而得到最终的水印图像。测试结果表明该算法满足了数字水印的不可见性和鲁棒性要求。

Digital Watermark Algorithm for Color Images Based on DCT

An algorithm for embedding color watermark image in color carrier image was realized.During the embedding stage,the carrier image was dived into blocks with the same size of the watermark image firstly;then,in DCT transforming domain,the transforming coefficients of the watermark image in R,G and B layer were embedded into the middle-low frequency coefficients in the corresponding layers of every block of the carrier image.During the extracting stage,the watermark images were extracted from every block of t...