图像内区域复制粘贴篡改鉴定

Identification of regional copy and paste tamper

区域复制粘贴篡改检测算法是以图像块匹配为基础的,然而传统的匹配算法计算量大,匹配速度慢,效率低下.针对现有的图像内区域复制粘贴检测算法计算量大,时间复杂度高的问题提出一种有效快速的检测与定位篡改区域算法.首先利用小波变换获取图像低频区域,然后对得到的图像低频部分进行分割,然后对分割后得到的每个图像块进行DCT变换,通过特征向量排序缩小匹配空间,最后通过经验阈值进行真伪鉴定,实验结果表明该算法过程中除掉图像冗余,减少检测块数,降低了时间复杂度,提高了检测效率。

The image regional copy and paste tamper detection algorithm is based on block matching, however, in the traditional template matching algorithm, complicated calculations cause a slow matching speed. In allusion to the complicate calculation problems in existing algorithm of image regional copy and paste tamper detection, we propose a algorithm to detect and locate tampered area fast and effectively In this paper, First, wavelet transform is used to obtain the low frequency area,and then segment the low frequency area of image. After that, to each image block got perform DCT transformation,narrowing the matching space by means of sorting feature vector. At last, identify the authenticity through the experienced threshold value. The experimental results show that the algorithm is to remove the image redundancy in the process, reduce test blocks, reduce the time complexity and improve the detection efficiency.