基于DCT变换的图象分块数字水印算法

数字水印是数字作品版权保护的重要技术手段,不可察觉性和鲁棒性是图象水印中基本要求,但它们却是一对互相制约的因素.该算法提出了一种新的数字水印嵌入和提取方法,以一幅图象作为水印,信息量大,优于通常把文本,字符作为水印的方法;分块随机嵌入提高了水印嵌入的顽健性;根据图象局部特征确定水印的嵌入强度,使水印的嵌入强度随图象局部特征变化而变化.针对典型攻击的实验结果表明该算法具有很好的鲁棒性.

A Digital Watermarking Algorithm Base on DCT And Blocked Image

Digital watermarking is s key technique for protecting intellectual property if digital media,Imperceptibility and robustness,which are the basic requirements of digital watermark,conflict with each other.A new watermarking embedding and detection method is presented.A grey image is embedded into another one.The entropy of image watermark information is greater than that of text or words watermark used in normal watermarking algorithms frequently;The algorithms could enhance the robusticity to non-geometric attack and loss compression,by embedding into DCT coefficients block random;The intensity of the watermark is based on the statistic feature of the original dates of the image so that the intensity of the embed watermarks is allowed to change with the local dates.The experimental results show that the effectivity and robustness of the digital watermarks.