基于投影数据主成分分析的图像篡改检测算法

摘要

Aimming at the defects of Posucue algorithm which is time-consuming in finding copy-paste forgery in image tampering, a new algorithm based on Principal Components Analysis(PCA) of projection features is put forward. A tampered image is divided into many overlapped small image blocks. The horizontal projection and vertical projection of each image block are gained to build up a matrix. Dimensionality reduction of this matrix is completed by PCA. Then Lexicographic Sorting is applied. With a threshold distance of each neighborhood block in the dimensionality reduced matrix, the copy-paste area can be found. Experimental result shows that this new algorithm can find the exact copy-paste areas and be more rapid than Posucue algorithm.%传统算法处理图像复制-粘贴型篡改问题时速度较慢.为此,提出一种基于投影数据主成分分析(PCA)的图像篡改检测算法.利用分块图像的行、列投影构建图像块投影特征矩阵,通过PCA对其降维,并使用字典排序法进行排序,结合图像块偏移置信距离判断图像复制-粘贴区域,完成被动取证.实验结果表明,该算法能准确找出篡改区域,与Posucue算法相比速度较快.