Abstract
Recently, varieties of biometric authentication systems were investigated and some of them came into practical use. Among them, face authentication has the advantage of being socially-acceptable as well as less demanding to users, because humans usually take the same measure to person identification in daily life. The system, however, should respond to a challenge made by "Masquerade" through the use of photographic portraits. Thus, a new scheme for preventing such type of masquerade is proposed in this paper. Since true human could hardly repress eyewinks, the basic idea is to detect them under the framework of template matching. What is characteristic about the proposed scheme is to prepare templates not only for the eye regions but also for other undeformable region of the face, such as around the nose. This would enable to distinguish the case when the eyes were lost of tracking because of rapid motion of the face from the case when true blinks were detected. When even a single blink has not been detected during a certain time period, the input face image is judged as a photographic portrait. Validity of the scheme for preventing masquerade in face authentication system was tested by experiments and fairly promising results were obtained.
