Copy-move tampering detection using affine transformation property preservation on clustered keypoints

Recent advances in multimedia technologies have made imaging devices and image editing tools ubiquitous and affordable. Image editing done with malicious intent is called as image tampering or forgery. The most common forgery is the copy-move forgery which involves copying a part of an image and pasting it on some other part of the same image. There are many existing methods for such forgery detection, but most of them are sensitive to post-processing and do not detect multiple instances of forgeries in an image. In the proposed approach, affine transformation property preservation of clustered keypoints in the image is used, which includes the tests for collinearity and distance ratio preservation. Our method is also able to detect multiple copy-move forgeries within an image. The proposed method is tested against four image tampering detection datasets, and the results of our method are the best compared to the existing eight state-of-the-art methods in terms of accuracy.