Digital image forensics: An affine transform robust copy-paste tampering detection

It became very easy today to capture and create digital photographs. It's no more a costlier affair, as most of the handheld electronic gadgets such as mobile phones are equipped with digital cameras. Today, there are ample PC and mobile apps available which are developed to manipulate captured photographs. One can easily take a picture, manipulate it with the installed app and make it viral through the internet. Hence, these digital photographs should not be interpreted as they speak. Digital images are the good proof of events and places. Hence, these digital photographs can be presented as evidence before a court of law. It becomes very important in such cases then, to prove the digital photographs in question to be original. Digital image forensics plays a vital role in such circumstances. Digital image forensics is a branch of digital forensics which deals with examining the digital photographs for their integrity and authenticity. In this paper, we present a digital image forensic method which can detect one of such image tampering. As images can be tampered in a number of ways, in this paper, we address a common case called as copy-paste tampering. Our proposed method is robust to affine transform; especially to rotation and scaling.