The Problem of Face Image Morphing in Identification Documents - Analysis, prevention and detection
Illias Batskos is a PhD student in the Department of Datamanagement & Biometrics. Promotors are dr.ir. L.J. Spreeuwers and prof.dr. D. Meuwly from the Faculty of Electrical Engineering, Mathematics and Computer Science.
This dissertation focuses on the problem of face image morphing in identification documents. Given the face images of two (or more) individuals, we can create a composite face image (a morph) using computer software that looks like both of them. One of the contributors (the accomplice) could use such a morph to apply for a new identification document, e.g. a passport. If that passport gets issued, the other contributor (the criminal) can then use it to conduct illegal activities and/or evade justice. This identity sharing scheme is known as a morphing attack and is a serious security vulnerability. In the first chapter, I introduce the subject of face morphing, talk about its historical use cases and analyse its causes and consequences. The second chapter is dedicated to improving morph generation algorithms, since being better prepared for what we might encounter in the real world is crucial. There, I present some improvements to a specific automated morph generation process, namely landmark-based morphing. The third chapter consists of a novel morphing prevention approach in ID document enrolment processes that, if implemented, would seriously limit the morphing attack threat. Next, I focus on morphing attack detection and present two methods based on image forensics that can be used to visualise morphing-related manipulation traces on digital images. Visualisation of morphing traces is very important as it can be used as evidence in a court of law. Finally, since the scale of the problem requires automated solutions, I use one of the aforementioned methods to create an automated morphing attack detection algorithm, so that any incriminating decision by the algorithm can be reviewed and explained by applying the corresponding image forensics method and visualising any possible traces.
