一种公开数字图象块相关自适应随机水印算法

提出了一种新颖的公开数字图象块相关自适应随机水印算法，该算法以一幅彩色图象作为水印信息使得隐藏的水印信息量大，优于通常把文本、字符作为水印的方法；在水印嵌入时根据原始图象自身的特性，自适应地调节嵌入深度来保证水印的不可见性；分块随机嵌入提高了水印嵌入的顽健性；利用块相关技术使得水印提取过程不需要使用原始图象和其他参数，实现了有真正实用价值的公开水印图象算法．通过实验验证，效果良好。

A Novel Public Digital Image Watermarking Algorithm

A novel public digital image watermarking algorithm for color images, by utilizing the technique of inter-block correlation of DCT coefficients, self-adjustment modification and random embedment, is proposed. It is embedded into color image watermark to DCT coefficients of color image luminance (Y) component. The entropy of image watermark information is greater than that of text or words watermark used in normal watermarking algorithms frequently. This algorithm can adaptively adjust the strength of embedded image watermark depending on the local feature of an original image to assure invisibility and maintain the quality of the original image. Further more, it could enhance the robusticity to non-geometric attack and loss compression, by embedding into DCT coefficients block random. Last but not the least, the embedded watermark can be extracted availably without the original image and the parameters used in embedding process, by utilizing the technics of inter-block correlation of DCT coefficients. Experimental results suggest that the proposed algorithm is one of the utilizing public watermark algorithm realizations.