An efficient and robust algorithm is proposed for detecting and localizing Copy-Move forgery. Firstly, discrete wavelet transform (DWT) is applied to a tampered image, then the low-frequency component in wavelet sub-band is divided into overlapped blocks. Seven statistics of each block are calculated and lexicographically sorted so that duplicated blocks are identified by searching for rows being closer to other rows after sorting. After finding out the duplicated region in the wavelet sub-band, the duplicated region can be found in the tampered image. Simulation results show the efficiency of the proposed algorithm.%为了快速有效地检测复制-粘贴(Copy-Move)图像篡改,提出了一种基于重叠块统计值的Copy-Move型篡改图像盲认证方式.该算法先将图像进行一次离散小波变换(Discrete wavelet transform,DWT)并取其低频部分分解为重叠块,接着统计各重叠块的7个统计值并计算重叠块间的相似性找出相似块,最后返回原篡改图像找出篡改部分.仿真结果表明,该方法能快速有效地检测出篡改部分经过JPEG有损压缩、高斯白噪声污染和这两者结合的篡改图像.
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