CAJ | 학술논문

　　基于离散余弦变换（DCT）的特点，提出一种自适应水印算法。选取 DCT 域三个中频系数及主对角线系数，并求它们各自的均值，比较嵌入位与这两个平均值的关系，调整嵌入位的大小自适应实现水印嵌入。利用 Arnold 变换对水印信息进行预处理，增强水印的安全性。实验表明，该算法水印提取效果较好，对剪切、旋转、修改、JPEG 等攻击具有较好的稳健性和鲁棒性。
　　기우리산여현변환（DCT）적특점，제출일충자괄응수인산법。선취 DCT 역삼개중빈계수급주대각선계수，병구타문각자적균치，비교감입위여저량개평균치적관계，조정감입위적대소자괄응실현수인감입。이용 Arnold 변환대수인신식진행예처리，증강수인적안전성。실험표명，해산법수인제취효과교호，대전절、선전、수개、JPEG 등공격구유교호적은건성화로봉성。
An adaptive digital watermarking algorithm is proposed based on the characteristics of discrete cosine transformation (DCT). Three medium frequency DCT coefficients and main diagonal coefficients are selected,and their means are calculated. The relation between the embedded coefficient and these two means are analyzed to achieve watermarking embedding adaptively by adjusting the value of embedded coefficient. The watermarking is preprocessed by Arnold transformation before being embedded to enhance the security of the algorithm. The experimental result shows that the algorithm has a good effect in watermarking extraction,as well as enough toughness and robustness for some common attacks,such as cutting,rotation,altering,JPEG compression,etc.