CAJ | 학술논문

为了提高水印的安全性、鲁棒性和不可见性,提出了一种基于Hilbert扫描和SVD(Singular Value Decomposition,奇异值分解)的小波域图像水印技术.算法以一幅有意义的二值水印图像为水印信号.首先对原始图像进行一层小波变换,对低频分量进行图像分块,并对每一个图像块进行SVD.利用了SVD的单向非对称性和正交矩阵的性质,给出了一种自适应水印方案.同时,利用了Hilbert扫描能很好地保持图像空间局部连接性的特点.然后,利用图像的局部统计特征自适应地修改阈值,利用两个阈值严格控制系数的修改程度,使算法达到不可见性和鲁棒性之间的最优平衡.水印的提取无需原始图像的参与,达到了真正的盲水印.实验结果表明,该算法是有效的,对常见的图像处理操作具有较强的鲁棒性.
위료제고수인적안전성、로봉성화불가견성,제출료일충기우Hilbert소묘화SVD(Singular Value Decomposition,기이치분해)적소파역도상수인기술.산법이일폭유의의적이치수인도상위수인신호.수선대원시도상진행일층소파변환,대저빈분량진행도상분괴,병대매일개도상괴진행SVD.이용료SVD적단향비대칭성화정교구진적성질,급출료일충자괄응수인방안.동시,이용료Hilbert소묘능흔호지보지도상공간국부련접성적특점.연후,이용도상적국부통계특정자괄응지수개역치,이용량개역치엄격공제계수적수개정도,사산법체도불가견성화로봉성지간적최우평형.수인적제취무수원시도상적삼여,체도료진정적맹수인.실험결과표명,해산법시유효적,대상견적도상처리조작구유교강적로봉성.
In order to improve the security,robustness and invisibility of a watermark,an image watermarking technology is proposed,based on the wavelet domain singular value decomposition and Hilbert scanning.The watermark signal is a binary watermark image.First, do a wavelet transform to the original image, then block to the low-frequency components, and foT all image blocks do singular value decomposition.SVD preserves both one-way and non-symmetric properties.According the characters of the orthogonal matrix after SVD,an adaptive image watermarking scheme is given by taking full advantage of Hilbert scanning. The threshold,which is used to modify the selected coefficients,is decided by the statistical properties of local blocks.The modification of coefficients is controlled by these two thresholds so as to obtain the optimal tradeoff between the invisibility and the robustness.At the same time,the watermark can be extracted without original image.It is truly blind watermark algorithm.The experimental results show that the proposed algorithm is effective,which is very robust to common image processing operations.