Robust Feature Extraction and Iris Recognition for Biometric Personal Identification

Humans have distinctive and unique traits which can be used to distinguish them from other humans, acting as a form of identification. A number of traits characterising physiological or behavioral characteristics of human can be used for biometric identification. Basic physiological characteristics are face, facial thermograms, fingerprint, iris, retina, hand geometry, odour/scent. Voice, signature, typing rhythm, gait are related to behavioral characteristics. The critical attributes of these characteristics for reliably recognition are the variations of selected characteristic across the human population, uniqueness of these characteristics for each individual, their immutability over time (Jain et al.,1998). Human iris is the best characteristic when we consider these attributes. The texture of iris is complex, unique, and very stable throughout life. Iris patterns have a high degree of randomness in their structure. This is what makes them unique. The iris is a protected internal organ and it can be used as an identity document or a password offering a very high degree of identity assurance. Also the human iris is immutable over time. From one year of age until death, the patterns of the iris are relatively constant (Jain et al.,1998, Adler,1965). Because of uniqueness and immutability, iris recognition is one of accurate and reliable human identification technique. Nowadays biometrics technology plays important role in public security and information security domains. Iris recognition is one of the most reliable and accurate biometrics that plays an important role in identification of individuals. The iris recognition method deliver accurate results under varied environmental circumstances. Iris is the part between the pupil and the white sclera. The iris texture provides many minute characteristics such as freckles, coronas, stripes, furrows, crypts (Adler,1965). These visible characteristics are unique for each subject. Iris recognition process can be separated into these basic stages: iris capturing, preprocessing and recognition of the iris region. Each of these steps uses different algorithms. Pre-processing includes iris localization, normalization, and enhancement. In iris localization step, the detection of the inner (pupillary) and outer (limbic) circles of the iris and the detection of the upper and lower bound of the eyelids are performed. The inner circle is located on the iris and pupil boundary, the outer circle is located on the sclera and iris boundary. Today researchers follow different methods in finding pupillary and limbic