  Face recognition is a widely used biometric approach. Face recognition
technology has developed rapidly in recent years and it is more direct, user
friendly and convenient compared to other methods. But face recognition systems
are vulnerable to spoof attacks made by non-real faces. It is an easy way to
spoof face recognition systems by facial pictures such as portrait photographs.
A secure system needs Liveness detection in order to guard against such
spoofing. In this work, face liveness detection approaches are categorized
based on the various types techniques used for liveness detection. This
categorization helps understanding different spoof attacks scenarios and their
relation to the developed solutions. A review of the latest works regarding
face liveness detection works is presented. The main aim is to provide a simple
path for the future development of novel and more secured face liveness
detection approach.
