抗几何攻击的空间域图像数字水印算法

Geometric Attack Resistant Image Watermarking in Spatial Domain

当前已有的水印算法多数无法抵抗几何攻击,而现有抗几何攻击的水印算法大多数只能抵抗一定程度内的几何攻击.本文提出了一个新的抗几何攻击的图像数字水印算法.该算法在水印嵌入时,先对原始图像进行分块,然后对各个子块图像根据量化策略重复嵌入相应的1bit水印信息;在水印提取时,先将含水印图像进行分块,然后对从各个子块图像中提取出的水印信息根据多数原则判定相应子块图像所含的1bit水印信息.该算法简单、快速,所能嵌入的水印信息量大,并且在提取水印时无需原始图像.实验结果表明,该算法能够有效地抵抗很大程度的几何攻击及其组合攻击,对常规的图像处理攻击也具有很强的稳健性.

Most existing watermarking algorithms cannot resist geometric attacks, while most geometric attack resistant watermarking algorithms can resist only some degree of geometric attacks. This paper proposed a novel geometric attack resistant imageatermarking algorithm. In the algorithm, for watermark embedding, the original image was divided into sub-images, and then one bit of the watermark information was embedded into each sub-image repeatedly by quantization. For watermark extracting, the watermarked image was divided into sub-images, and then one bit of the watermark information of each subimage was obtained by majority rule from watermark information extracted from the sub-image. The algorithm is simple and executs rapidly. The quantity of embedded watermark informa- tion is large and the original image is not needed for watermark extracting. Experimental results show that the algorithm can very effectively resist large degree of geometric attacks and compound attacks, and it is also strongly robust against common image processing attacks.