Geometric Tampering Estimation by Means of a SIFT-based Forensic Analysis

In many application scenarios digital images play a basic role and often it is important to assess if their content is realistic or has been manipulated to mislead watcher's opinion. Image forensics tools provide answers to similar questions. This paper, in particular, focuses on the problem of detecting if a feigned image has been created by cloning an area of the image onto another zone to make a duplication or to cancel something awkward. The proposed method is based on SIFT features and allows both to understand which are the image points involved in the counterfeit attack and, furthermore, to recover the parameters of the geometric transformation. Experimental results are provided to witness the powerfulness of the proposed technique.