摘要
提出了一种在数字图像中水印嵌入强度的最优估计方法。对基于一次B啨zier曲线融合方式的嵌入规则进行了研究。在水印图像的提取过程中,水印强度因子的选择是基于极大似然估计方法。对基于一次B啨zier曲线融合方式的嵌入规则与加法、乘法嵌入规则的峰值信噪比进行比较,可以看出前者嵌入水印的峰值信噪比高于另外两种嵌入方法,人类视觉系统不能发觉嵌入了水印的隐秘图像与原始图像的差别;在不知道嵌入水印强度因子的前提下,可根据对水印强度因子的估计,从隐秘图像中将水印提取出来,而且提取效果令人满意;水印图像由二值图像推广到非二值图像。
In this paper, an optimal estimation of the embedding strength for the digital image water-mark is discussed. Under the assumptions that the original image data are an i. i. d. random sequence from a Guassian distribution, it's shown that this embedding strength should be estimated by observing the averages of the watermarked image and briefly calculating between them. The approach is based on maximum-likelihood estimation of the watermark embedding strength. The experimental results show that this method is effective for watermark extraction. Moreover, according to the addition, multiplication and fusion embedding rules, their performances are compared and analyzed using PSNR. The conclusions obtained by experiments are useful to future research.
出处
《红外与激光工程》
EI
CSCD
北大核心
2004年第2期174-177,共4页
Infrared and Laser Engineering
基金
国家自然科学基金项目资助(F60085002)
中国科学院信息安全国家重点实验室开放课题基金(03-02)
湖北省教育厅重点基金项目资助(2003A012)
