CAJ | 학술논문

为提高图像篡改检测与恢复性能，提出一种基于块特征与混沌序列的图像认证水印方案。对2×2分块离散余弦变换系数编码产生块特征，嵌入到其他图像块像素的低两位，块嵌入的映射关系通过混沌序列产生；结合奇偶检测法对常规的认证方式进行改进，并通过提取有效块的特征信息实现被篡改区域的自恢复。试验表明，该方案嵌入水印信息量少，安全性高，对常规篡改可进行精确定位，并能较好的实现自恢复，还可以有效地检测出仅图像内容的攻击。
위제고도상찬개검측여회복성능，제출일충기우괴특정여혼돈서렬적도상인증수인방안。대2×2분괴리산여현변환계수편마산생괴특정，감입도기타도상괴상소적저량위，괴감입적영사관계통과혼돈서렬산생；결합기우검측법대상규적인증방식진행개진，병통과제취유효괴적특정신식실현피찬개구역적자회복。시험표명，해방안감입수인신식량소，안전성고，대상규찬개가진행정학정위，병능교호적실현자회복，환가이유효지검측출부도상내용적공격。
To improve the performance of images tamper detection and recovery,an authentication watermarking scheme based on block features and chaotic sequence was presented.For each block of size 2 ×2 pixels,discrete cosine trans-form(DCT)coefficients were used to generate watermarking and embedded into the two least significant bits of its map-ping block which was determined by chaotic sequence.The conventional authentication methods were improved by com-bining parity detection and the tampered region could be self-recovered by extracting characteristic information of the valid block.Experimental results demonstrated that the proposed method not only improved the quality and security of watermarked images,but also could detect tampered regions accurately and reconstruct images while keeping the recog-nition quality.Additionally,the scheme was not vulnerable to the content-only attack.