A review of multimodal facial biometric authentication methods in mobile devices and their application in head mounted displays

Recently, user authentication has become more important as electronic items become part of the Internet of all Things and users own more mobile devices. Biometric authentication systems have made a promising stride toward reaching the balance of a strong and stress-free authentication by using the distinctiveness of the user's characteristics to determine valid users. Biometric authentication has gained popularity as the system for implicit, non-intrusive and progressive authentication because it has no memory load or carry-along requirements. Here, we review the state-of-the-art in facial biometrics research and we examine facial authentication techniques and the emerging usage of multi-modal biometrics such as various combinations of periocular, iris and face biometrics to ensure better user security. The miniaturization of advanced facial authentication hardware systems into mobile devices such as mobile phones and head-mounted displays (HMDs) used for VR/AR/MR has made biometric authentication seamless. Our survey examines facial authentication based on IR LED and multi-spectral cameras as they are the most commonly implemented hardware due to their multi-functional usage. We examine the possible application of these technologies within HMDs and the most recently released mobile phone devices on the market.