提出一种具有几何不变性的复制-粘贴盲鉴别算法。该算法首先定义灰度级别和灰度结构，根据像素的灰度级别划分图像块，再结合其灰度结构定位可疑块对；然后对每一组可疑块对进行基于对数极坐标变换的相位相关，并粗略定位篡改区域；最后，精确计算篡改区域之间的旋转角度、缩放尺度及平移量，从而定位复制-粘贴区域。实验结果表明，该算法不但具有旋转、缩放等几何不变性，而且具有较高检测效率及较强的鲁棒性。%A blind identification algorithm for image copy-paste tampering with geometric invariance was proposed in this study.Firstly,gray level and gray structure are defined,the image is divided into blocks according to the gray levels of pixels,and the suspicious blocks in the image is positioned through the gray structure;Secondly,phase correlation is made for each group of suspicious block based on logarithm polar coordinate transformation,and the tampering regions are located preliminarily;Finally,the rotation angle,scale and translation measurements are calculated precisely,and the tampering re-gions are positioned.The experimental results show that our algorithm performs well against copy-rotate/scale-paste tampe-ring,and its detection efficiency and robustness are better than the existing algorithms.
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