基于小波包变换的图像数字水印算法  

An Image Watermarking Algorithm Based on Wavelet-Packet Transform

作　　者：黄伟[1] 张雪艳[1] 柳亚婷[2] HUANG Wei,ZHANG Xue-yan,LIU Ya-ting（1.Institute of Meteorology,PLA University of Science and Technology,Nanjing 211101,China;2.Engineering Institute of Engineer Corps,PLA University of Science And Technology,Nanjing 210007,China）

机构地区：[1]解放军理工大学气象学院,江苏南京211101 [2]解放军理工大学工程兵工程学院,江苏南京210007

出　　处：《电脑知识与技术》2010年第5期3434-3436,3446,共4页Computer Knowledge and Technology

摘　　要：提出一种基于小波包变换和人类视觉特性的自适应盲水印算法。该算法选择原始图像小波包变换的中频子带进行嵌入,提高了水印的容量和不可见性;采用双极性量化方法嵌入水印,根据嵌入强度自适应地确定量化步长,提取时无需使用原始图像。实验证明该算法对常见的图像处理攻击具有良好的鲁棒性,同时也很好地保证了水印的不可见性。An image watermarking algorithm based on wavelet-packet transform is proposed.The algorithm chooses middle subband of the wavelet-packet decomposition of the original image to embed the watermark,which increases the capacity of the watermark and improves the imperceptibility also.The watermark is embedded by quantizing the wavelet packet coefficients,and the quantizing step is calculated according to the embedding strength.The watermark can be distilled without the original image.Experiment data shows that the algorithms has good robustness,and the imperceptibility of watermark can be guaranteed at the same time.

关 键 词：数字水印 小波包变换 人类视觉特性 量化 鲁棒性 

分 类 号：TP309[自动化与计算机技术—计算机系统结构;自动化与计算机技术—计算机科学与技术]