“…Biometrics are divided into: - Static or permanent characteristics . Static biometrics are mostly physical features which do not change or the changes are minor over the life span such as fingerprints (Jain et al ., 2001), palm prints (Li et al ., 2010), face dynamics (Connolly et al ., 2012), retina (Saraswathi et al ., 2011), iris (Sanchez-Avila and Sanchez-Reillo, 2005), tongue shape (Huang et al ., 2010), etc.
- Dynamic or soft characteristics . Dynamic or soft biometrics are behavioral characteristics which change rapidly such as gait (Kale et al ., 2004), keystroke dynamics (Bergadano et al ., 2002), handwriting (Ramann et al ., 2002; Ballard et al ., 2006), lip movement (Luettin et al ., 1996; Shipilova, 2006), voice/speech (Sanderson and Paliwal, 2001), blinking (Westeyn et al ., 2005), etc.
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