一种基于小波变换的非均匀量化索引调制水印算法  

A Nonuniform Quantization Index Modulation Watermarking Algorithem Based on Wavelet Transform

作　　者：熊淑华[1] 卜云[2] 周激流[3] 付媛媛[1] 

机构地区：[1]四川大学电子信息学院,四川成都610064 [2]电子科技大学通信学院,四川成都610054 [3]四川大学计算机学院,四川成都610064

出　　处：《四川大学学报（工程科学版）》2006年第3期140-143,共4页Journal of Sichuan University (Engineering Science Edition)

摘　　要：为了提高数字水印的稳健性与不可见性,将图像小波变换与量化索引调制算法相结合,提出了一种基于小波变换的非均匀量化索引调制数字水印算法。该算法对原始图像进行离散小波变换,将中频小波系数分成3×3的系数子块作为水印载体,对子块的系数均值采用非均匀量化索引调制,实现二值水印的嵌入。根据人类视觉特性,不同的系数子块采用不同的量化间隔并自适应于子块内相邻系数的差值。实验结果表明,该算法透明性好,安全性高,对高斯白噪声、剪切、滤波以及JPEG压缩等常见攻击具有较强的稳健性。A nonuniform quantization index modulation watermarking algorithm based on image wavelet transform was presented to improve the robustness and invisibility of digital watermark. By taking discrete wavelet transform of original image, the middle-frequency wavelet coefficients, which were divided into small blocks, were selected as carrier of watermark information. A two-value watermark sequence was embedded into the mean values of block coefficients by applying non-uniform quantization index modulation. According to human vision system, different blocks used different quantization steps and were adaptive to the difference of adjacent coefficients. Experimental results showed that this algorithm can get a watermarked image with perceptual invisibility, high security and strong robustness against common image attacks.

关 键 词：数字水印 离散小波变换 非均匀量化索引调制 

分 类 号：TN911.73[电子电信—通信与信息系统]