FACIAL SOFT BIOMETRICS - Library of Ph.D. Theses | EURASIP

13Table 2: Table of Facial soft biometric traitsSB trait Algorithm DatabaseSkin color Deduced from [KMB] FERETHair color Deduced from [ZSH08] FERETEye color Own developed UBIRIS2Beard Own developed FERETMoustache Own developed FERETGlasses Deduced from [JBAB00] FERETFigure 6: ROI for the set of facial soft biometrics. Outlier filtering was a function of the standarddeviation σ and the meanµfor each of the H,S and V parameters.estimation algorithms are featured, along with the related experimental results. We then proceedto focus on eye color as a soft biometric trait and examine an automatic eye color classifier inchallenging conditions, such as changing illumination, presence of glasses and camera sensors.User acceptance study relating to soft biometricsFinally we conclude with a usability study that verifies the user acceptance of SBSs, specificallywhen compared to existing PIN or fingerprint access control systems.The pervasiveness of biometric systems, and the corresponding growth of the biometric marketsee [usa11a], has successfully capitalized on the strength of biometric-based methods in accuratelyand effectively identifying individuals. As a result, modern state-of-the-art intrusion detection andsecurity systems include by default at least one biometric trait. It is the case though that little emphasishas been given to better understanding user-acceptance and user-preference regarding suchsystems. Existing usability related works, such as in [CAJ03] and [LBCK03], focus on establishingfunctional issues in existing ATM machines, or on studying the influence of user interactionon the performance of fingerprint based systems (see [KED11]) and interfaces (see [RJMAS09]).Other interesting works (see [usa11b], [CG05], [CJMR09]), analyze possible methods that improveinterface design. Our emphasis here is on providing insight on the attitudes and experiencesof users towards novel and emerging biometric verification methods, and to explore whether suchnovel biometric technologies can be, in terms of user acceptance, valid alternatives to existingprevalent PIN based systems. Our focus, in addition to considering the traditional PIN-basedmethod, is to explore the usability aspects of systems based on classical biometrics such as fingerprintand face recognition, and to then proceed to study the usability of systems based on theemerging class of soft-biometric methods. Our evaluation is based on having the users rate andrank their experiences with different access methods.