Decoupling texture blending and shape warping in face morphing

Automatic face recognition systems (FRS) are quite sensitive to the well-known face morphing attack, as pointed out by several researchers. Considering that, in the perspective of a fraudulent document usage, a criminal would certainly do its best to fool both humans and FRSs, the design of effective countermeasures should consider the trickiest and challenging conditions. Cognitive studies show that facial texture and shape (the two main components modified by face morphing) play a different role in face recognition by humans. This paper aims at understanding the behavior of FRSs with respect to these two factors and to identify the morphing parameters that maximize the probability of a successful attack.