I. Introduction
Due to the widespread deployment of biometric-based identification and verification of individuals, it is essential to observe a biometric characteristic that is reliable, user-friendly and easy to capture. Face biometrics is well suited for this purpose due to its popularity and widespread use for biometric authentication. Moreover we consider the ease of capturing from a distance in a non-intrusive manner and also the recently achieved high recognition accuracy. These properties further enable that face recognition is to be used in various applications that are attributed with high security requirements like border control. However, biometric face recognition systems (FRS) are known to be highly vulnerable to presentation attacks (aka., spoofing attacks) against the capture device [14]. In addition face recognition system can be deceived during the enrolment process by providing manipulated images [4].