Limitation of PFA-events as a forensic tool

Purple Fringes are aberrations or defects in the camera sensor profile which are spotted in the vicinity of edges near high contrast regions. Since these defects are very device centric, they become potential Forensic Tools for detection and identification of splicing operations in natural images. In existing literature, these fringe patterns are localized and mapped to what are known as Directive PFA-events. It was claimed in existing literature, that this swarm of directional PFA-events will exhibit a convergence towards the image centre for authentic images and a divergence for spliced images. By re-creating the PFA-event synthesis process for both authentic and forged images, we demonstrate both with rational arguments and experimental evidence that this convergence is not possible. This dismisses the PFA-event based approach as a Forensic Tool, without ruling out other secondary features which may be derived from the fringe regions for forensic analysis.