分形理论在增强数字水印顽健性方面的研究

基于自相似分形集抗几何失真的特性和人眼的视觉系统特征，提出了一种首先利用
频域变换确定水印嵌入区，然后将数字水印信息转化为生成自相似分形集的IFS 系数，再把由该IFS 生成的自相似分形图嵌入到图像中的数字水印算法。并对该数字水印算法抗几何攻击性以及不可感知性进行了检验。
关键词∶迭代函数系（IFS）；人眼视觉系统（HVS）；掩蔽效应 ； 数字水印

Study of Fractal in building up the Digital Watermark’s Robusting (1.School of Science, Lanzhou University of Technology, Lanzhou 730050 China ,2. School of Computer and Commucation ,LanZhou University of Technology ,LanZhou ,china, 730050） Abstract: Based on the strongly robusting character against geometric distortion of self-similar fractal and the character of Human Visual System(HVS),a new algorithm for digital watermark is put forward。The method operates in the frequency domain and spatial domain. The digital watermark information is transformed into coefficients of an IFS after the original image has been done frequency transformation, and then the self-similar fractal image created by this IFS is embedded into the special area of the image. The algorithm is tested in robusting against
geometric distortion and of imperceptibility of human eyes.
Keywords: iterated function system; human visual system; visual masking; digital watermarking