CAJ | 학술논문

针对单镜头视频时域篡改问题，提出一个以内容相似性为基础的视频篡改被动盲检测算法。通过高斯金字塔变换获得视频帧的3种尺度视觉内容，根据信息论定义相邻两帧的归一化平均互信息，采用线性组合构建多尺度归一化互信息描述子，实现相邻两帧多尺度视觉内容相似性的度量。利用局部离群点检测算法计算视觉内容相似性异常度，使用阈值法检测视频篡改位置。实验结果表明，该算法不仅能有效地检测出视频帧删除、复制以及插入3种篡改的位置，而且适用于不同编码格式视频间和同源的篡改。在检准度和检全率上优于现有的时域篡改检测算法。
침대단경두시빈시역찬개문제，제출일개이내용상사성위기출적시빈찬개피동맹검측산법。통과고사금자탑변환획득시빈정적3충척도시각내용，근거신식론정의상린량정적귀일화평균호신식，채용선성조합구건다척도귀일화호신식묘술자，실현상린량정다척도시각내용상사성적도량。이용국부리군점검측산법계산시각내용상사성이상도，사용역치법검측시빈찬개위치。실험결과표명，해산법불부능유효지검측출시빈정산제、복제이급삽입3충찬개적위치，이차괄용우불동편마격식시빈간화동원적찬개。재검준도화검전솔상우우현유적시역찬개검측산법。
Aiming at the time tampering problem in the single video shot, a new algorithm based on the content similarity is proposed to detect the tampers of frame duplication, deletion and insertion. Firstly, the three-scale visual contents are obtained by using the Gaussian pyramid transform on every frame. Then,the normalized mutual information is defined on the single scale visual content of adjacent frames based on information theory. And the descriptor of multi-scale normalized mutual information is computed by linear combination. Thirdly,the abnormal degree of content similarity is computed by local outlier detection algorithm. Finally,the forgery places are detected by threshold. Experimental results show that the proposed algorithm can effectively localize the tamped position of the frame duplication,insertion,deletion tampers,and can be fit for the forgery of different coding formats and different cameras. The results also show that the proposed algorithm outperforms the existed algorithms in terms of precision and recall.