一种自适应的彩色图像水印算法

提出了一种新颖的彩色图像水印算法，算法利用DCT系数块之间的相关性将水印嵌入到彩色图像亮度分量Y的DCT系数中，在提取过程中无需使用原始图像和其它参数。它可以根据原始图像的特征自适应地调节水印的嵌入强度，使得盗版者难以估计嵌入的位置。实验表明，本算法较好保持了原始图像的品质，对非几何攻击和有损压缩具有较好的稳健性。

An Adaptive Digital Watermarking Algorithm for Color Images

The advent of the Internet and the wide availability of computers, scanners and printers make digital data acquisition, exchange and transmission easy. Digital watermarking techniques are proposed as a solution to the problem of copyright protection of multimedia document. This paper proposes a novel digital watermarking algorithm for color images. By using inter-block correlation of DCT coefficients, it is embedded into watermark to DCT coefficients of color image luminance (Y) component. The watermark can be extracted without the original image and the parameters used in embedding process. The algorithm can adaptively adjust the strength of embedded watermark depended on the local feature of an image. It is difficult for pirate to predict the position of embedded watermark. Experimental results show that the algorithm maintains the quality of the original image and is robust to non-geometric attack and loss compression.