基于特征的易碎图像水印框架

提出了一种基于特征的易碎图像水印框架,来阻止VQ攻击.图像特征被提取出来,用 来处理原始水印或生成水印,使得要嵌入的水印信息不仅不被攻击者知道,而且依赖于原始图 像.因此,不同的原始图像嵌入了不同的水印信息,从而使得攻击者无法建立VQ码表,因而无法 实现VQ攻击.同时,为了提高水印的安全性和篡改的局部检测性,本文给出了该框架下水印嵌 入方法的基本要求.根据该易碎图像水印框架,本文设计了一种基于图像矩不变量的易碎水印算 法.分析和实验结果表明,该算法不仅可以很好地、局部地检测图像中的篡改.即使图像中仅有一 位被篡改时.同时,在不需任何额外的密码或图像索引号的情况下,成功地抵抗VQ攻击.

Feature Based Fragile Image Watermarking Framework

A feature based fragile image watermarking framework is proposed to resist vector quantization (VQ) attack. Image features are extracted to process the original watermark or generate the watermark so that the embedded watermark is not only unknown to the attacker, but also dependent on the image. Therefore, different images have different embedded watermarks so that it is impossible for the attacker to build VQ codebook. At the same time, the watermark is embedded into the image under consideration of security and localization. The basic requirements for the embedding scheme are given for the trade-off between the security and localization. An actual moment invariants based fragile image watermarking scheme is presented to demonstrate our fragile watermarking framework. Analysis and experimental results demonstrate that our algorithm can simultaneously detect even one bit image alteration with graceful localization and resist vector quantization attack without the need of any unique keys or image indexes.