Introduction
FR is an attractive biometric for the reliable identification of individuals because of its non-intrusive nature, ease of integration into existing systems, and its potential to identify individuals at a distance without subject cooperation. These attributes make the technology ideal for the screening of individuals at borders, airports, secure facilities, etc. However, most of the current efforts in FR use a 2D representation of a face, and while much progress has been made, systems are severely compromised when subject to facial pose and scene lighting variations. In addition, the task of positive identification becomes increasingly difficult when confronted with large numbers of people to screen. 3D FR has the potential to handle some of these issues and is currently being explored in both academic and commercial environments. A thorough review of 3D FR academic research is presented in [20]. In addition, some commercial systems are discussed in [21].