Copy-move forgery detection from printed images

Counterfeiting digital images through a copy-move forgery is one of the most common ways of manipulating the semantic content of a picture, whereby a portion of the image is copy-pasted elsewhere into the same image. It could happen, however, instead of a digital image only its analog version may be available. Scanned or recaptured (by a digital camera) printed documents are widely used in a number of different scenarios, for example a photo published on a newspaper or a magazine. In this paper, the problem of detecting and localizing copy-move forgeries from a printed picture is focused. The copy-move manipulation is detected by verifying the presence of duplicated patches in the scanned image by using a SIFT-based method, tailored for printed image case. Printing and scanning/recapturing scenario is quite challenging because it involves different kinds of distortions. The goal is to experimentally investigate the requirement set under which reliable copy-move forgery detection is possible. We carry out a series of experiments, to pursue all the different issues involved in this application scenario by considering diverse kinds of print and re-acquisition circumstances. Experimental results point out that forgery detection is still successful though with reduced performances, as expected.