一种基于直方图的可逆数字水印算法

文中提出一种可逆数字图像水印算法的改进方案,防止了原有算法中可能出现的像素值溢出情况。改进后的算法利用图像的灰度直方图,在图像进行分块的基础上进行像素灰度值的修改,实现在图像的空间域中嵌入较为充沛的水印信息。其中标志点的设定,可以有效防止灰度值在修改过程中出现上溢和下溢的情况,而密钥的使用不仅加强了水印信息的安全性,同时简化原有算法,减少了繁琐的记录信息。实验结果表明,算法在嵌入大量水印信息的情况下仍能取得满意的PSNR值。

A Histogram-Based Algorithm for Reversible Digital Watermarking

Presents an improving method of reversible watermarking algorithm,and the method prevents over-flows in the original algorithm.Using the histogram of an image and its blocks,can embed a large amount of data by modifying the values of pixels.A flag point is set to prevent over-flows.The key is used to reinforce the security of watermarking and predigest the original algorithm,reduce some record data.Some experiment results are given,showing that the algorithm presented is feasible and can get satisfactory PSNR.