面向小波域的加权分数阶微积分图像数字水印新算法  

New image digital watermark algorithm with weighted fractional calculus based on wavelet coefficients

作　　者：刘磊[1,2] 苗启广[2] 石程[2] 

机构地区：[1]桂林电子科技大学计算机学院,广西桂林541004 [2]西安电子科技大学计算机学院,西安710071

出　　处：《计算机应用》2011年第11期3048-3052,共5页journal of Computer Applications

基　　金：国家自然科学基金资助项目(61072109);西安市科技局项目(CXY1015(3));中央高校基本科研业务费资助项目(JY10000903015)

摘　　要：针对现有加密技术易被破解,算法缺乏初值敏感性的问题,提出了一种采用分数阶微分和交换小波变换系数的图像数字水印的新算法。该算法充分利用了分数阶微分阶次具有极强的敏感性的特点,首先采用分数阶Cauchy公式对正弦信号做两个不同阶次的微分,同时将微分信号分别采样后加权叠加成伪随机序列;然后用此伪随机序列置乱水印,通过交换Haar小波分解的载体图像的高频系数将置乱水印嵌入载体图像。实验结果表明,提出的新算法能经受多种常见图像处理的攻击,具有较强的鲁棒性和较好的不可见性,能够实现较好的图像数字水印效果。Concerning the facts that the current encryption technology is susceptible to cracking and the sensitivity of initial value is lacking,a new digital watermark algorithm,based on fractional calculus and wavelet transform,for still images was proposed.It made full use of the characteristic that the fractional order is highly sensitive.The algorithm made sinusoidal signal by fractional Cauchy formula with two differential orders.The sampled signals of the differential signals were superimposed as the pseudo-random sequence which was used to scramble the watermark.By exchanging the high-frequency coefficients of the carrier image,the scrambled watermark was embedded into the carrier image.Several experiments to verify the proposed method were given and the results show that this novel algorithm is robust to a number of regular geometric attacks and other image processing operations.The new method is of good both robustness and invisibility.

关 键 词：数字水印 分数阶微分 小波变换 微分阶次 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]