基于混沌映射的脆弱水印算法

该文基于分层技术能够精确定位篡改位置及有效抵抗VQ攻击的思想，提出了一种用于图像篡改定位和恢复的脆弱性水印算法。利用斜帐篷映射产生的随机数作为密钥来产生认证水印，将映射分块的高六位平均值作为恢复水印，最后将水印信息嵌入到块的最低两位中。嵌入块的位置运用超混沌序列计算产生，具有高随机性。认证中利用分层技术，逐层对水印进行篡改定位及修复。实验结果表明，该算法具有良好的篡改定位及修复能力，能够有效抵抗VQ矢量攻击及恒均值攻击。

Fragile Watermarking Scheme Based on Chaotic Map

Based on layering technology sustaining the superior location accuracy and effective thwarting VQ attacks idea , we propose a method for image tamper localization and recovery fragile watermarking algorithms . Using the skew tent map to generate a random number as a key to generate the authentication watermark , the high six bits of the block average value from the map block compose the retrieving watermark , the watermark information is embedded in the last two bits of the block .Embedded block location calculation using the ultra chaotic sequence generated with high randomness .Authentication using layering technology layers and the watermark tamper localization and repair .Experimental results show that the algorithm has good tamper localization and repair capacity which can effectively resist attacks and constant mean vector VQ attack .