基于差值二次可扩展性的彩色图像可擦除水印  

Erasable Watermarking for Color Images Based on Twice Expandability of Difference

作　　者：熊志勇[1,2] 王丽娜[2] 

机构地区：[1]中南民族大学计算机科学学院,武汉430074 [2]武汉大学计算机学院,武汉430072

出　　处：《中南民族大学学报（自然科学版）》2010年第4期82-88,共7页Journal of South-Central University for Nationalities：Natural Science Edition

基　　金：中南民族大学中央高校基本科研业务费专项资金资助项目(ZZY10006)

摘　　要：提出了一种基于差值二次可扩展性的彩色图像可擦除水印算法.利用色彩分量之间的相关性减小差值,将较小的差值扩展量分散到2个色彩分量中,从而减小像素值的修改量,提高含印图像的质量.采用修改像素值LSB的方法嵌入水印,并利用差值的二次可扩展性定位不可扩展差值,采用调整临界像素值的方法避免像素溢出,在另一色彩分量中嵌入少量的辅助信息代替定位图,确保水印的嵌入率达到最大值.实验结果表明,该算法嵌入的水印不可见性好,在擦除水印后能够无损地恢复原始图像.This paper proposed an erasable watermarking algorithm for color images based on twice expandability of difference. The algorithm uses correlation of color components to decrease difference and disperse smaller expansion to two components, and the quality of watermarked images is improved evidently. The embedding scheme uses LSB replacing method to embed watermarking, and makes use of twice expandability to locate the position of un-expandable difference, and adopts pixel value adjusting method to prevent overflow or underflow. A few auxiliary information is embed in another component to replace location map, snsuring the maximum embedding capacity. Experimental results show that the algorithm can assure good imperceptibility for watermarked image and the image can be restored losslessly after the watermarking is erased.

关 键 词：可擦除水印 二次可扩展性 预测误差差值扩展 图像认证 篡改定位 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]