摘要
小波变换具有时频局部化特性和与人眼视觉特性相符的变换机制,而混沌序列具有确定、似随机、不可预测等特性。结合两种技术的优点,提出了一种基于混沌序列与小波变换的混合型数字水印算法,利用混沌映射产生一个密钥来克服有效字长效应,同时提高算法的抗破译性。实验结果验证了本文方法的有效性,能有效克服裁减、压缩、高斯噪声等攻击,比单一混沌系统或单一小波变换具有更强的抗破译性。
The discrete wavelet transform (DWT) has a localized characteristic in time-frequency domain and a transform mechanism that accords with human visual system. And chaotic sequence has such attributes as certainty, random-like and unpredictable. In order to make good use of the advantages of the two technologies, a mixed digit watermarking algorithm was presented. The new algorithm combined chaos sequence with DWT and utilized chaos mapping to generate a key, which could avoid the finite word length effects and improve its resistance to the attack of crypt analysis. The experimental results verify the validity of above algorithm. They also prove that it can overcomes attacks from reduction, compression and Gaussian noise and have a stronger resistance to the attack of crypt analysis than a single chaos system or a single DWT.
出处
《计算机应用》
CSCD
北大核心
2006年第6期1340-1342,1345,共4页
journal of Computer Applications