1.1 Biometrics
Biometrics is an emerging field of information technology which aims to identification of an individual. Biometric identifiers are the distinctive, measurable characteristics used to label and describe individuals (Jain, Hong, & Pankanti, 2000). Biometric identifiers are often categorized as physiological versus behavioral characteristics (Jain, & Ross, 2008).. It has been shown that information characteristics of each individual can be extracted in order to verify the identity of that individual in a population. Biometric based identification is more reliable than token based system (card, key, and etc.), and face recognition among biometric identification systems are natural and does not have less negative responses in using from peoples, and thus much more research efforts have been pouring into this area among biometric areas (Zhao, Chellappa, Phillips, & Rosenfeld, 2003). (Li, & Jain, 2004)
Biometrics authentication (or realistic authentication) is used in computer science as a form of identification and access control (Jain, Ross, Nandakumar, 2009). It is also used to identify individuals in groups that are under surveillance. Biometric authentication requires comparing a registered or enrolled biometric sample (biometric template or identifier) against a newly captured biometric sample (for example, captured image during a login). During enrollment a sample of the biometric trait is captured, processed by a computer, and stored for later comparison.
Biometric recognition can be used in mode, where the biometric system identifies a person from the entire enrolled population by searching a database for a match based solely on the biometric. Sometime identification is called “one-to-many” matching. A system can also be used in mode, where the biometric system authenticates a person claimed identity from their previously enrolled pattern this is also called “one-to-one matching. In most computer access or network access environments, verification mode would be used. The main advantages of biometrics over other standard security systems are that biometric traits cannot be forgotten or lost. They are difficult to copy, share and distribute and they require the person to be present at the time of authentication.
1.2 Face as a Biometric
Facial images are the most common biometric characteristic used by humans to make a personal recognition, hence the idea to use this biometric in technology. Face verification involves extracting a feature set from a two-dimensional image of the user's face and one method to proceed by comparing selected facial features from the image and a facial database. Face recognition is a challenging task for the researchers, on one side its applications is used for verification and recognition on other side it is complicated to implement due to all different situation that a human face can be found. The most popular approaches to face recognition are based on either the location or shape of facial attributes such as eyes, eyebrows, nose, lips and chin. For best work of facial recognition system in practice, it should automatically
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Detect whether face is available in the acquired image.
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Locate the face if there is only one face and,
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Recognize the face.
Face recognition is a process does not require active co -operation of a person so without instructing the person can recognize the person, so face recognition is much more advantageous compared to the other biometrics. Face recognition has a high identification or recognition rate of greater than 90 percent for huge face databases with well-controlled pose and illumination conditions.