Copy-move forgery detection based on PatchMatch

In this work we propose a new algorithm for copy-move forgery detection and localization, based on the fast computation of a dense nearest-neighbor field. To this end, we use PatchMatch, an iterative randomized algorithm for nearest-neighbor search, which exploits the regularity of natural images to converge very rapidly to a near-optimal and smooth field. We modify the basic algorithm to gain robustness against rotations, while keeping the original computational efficiency. Experimental results show the proposed technique to outperform almost uniformly all tested reference techniques in terms of both accuracy and speed.