直方图2Bin多进制图像数字水印算法的研究

具有低失真、强鲁棒等特点的直方图数字水印算法，一直是信息隐藏领域研究的热点.本文在分析现有直方图数字水印算法的基础上，提出并设计了基于直方图修改的2Bin多进制图像水印算法.以三进制为例，设计实现了2Bin三进制图像数字水印算法.在设计的算法中，根据嵌入的水印信息容量和载体图像的大小调整算法嵌入阈值，在维持直方图相邻2Bin高低形状不变的情况下，确定修改像素数目以及分块策略，实现水印信息的嵌入和提取操作.实验结果表明，该方法能够智能均衡载体图像质量和水印容量，同现有算法相比，大大提高了水印嵌入容量和水印嵌入后的图像质量，且能抵抗裁剪、旋转等传统的几何攻击和信号处理攻击.

A Histogram-Based 2Bin M-ary Image Digital Watermarking Algorithm

The histogram shape-based digital watermarking,which has the characteristics of low distortion,strong robustness,and etc,has become a hot topic in information hiding fields.Upon the basic properties of the existing histogram shape-based digital watermarking,a modified histogram shape-based 2Bin M-ary digital watermarking algorithm is designed firstly,and then,a concret ternary digital watermarking as an example of the M-ary system is further implemented.In the designed algorithm,the embedding threshold is adjusted according to the embedded watermark information capacity and the size of the carrier image.Under the condition of maintaining the high or low shape of the adjacent 2Bin histogram unchanged,the modified pixel number and the block strategy are determined to realize the embedding and extraction of watermark information.Experimental results show that this method is able to balance the relationship between image quality and watermark capacity intelligently,and that it greatly improves embedding capacity and image quality compared to these existing algorithms,meanwhile equips with the ability to resist the traditional geometric attacks and common image processing operations.