121 Copyright © 2010, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Chapter 6 Gabor Wavelets in Behavioral Biometrics M. Ashraful Amin City University of Hong Kong, Hong Kong Hong Yan City University of Hong Kong, Hong Kong IntroductIon Biometrics involves the development of statisti- cal and mathematical methods applicable to data analysis problems in the biological sciences. More specifically, the term “biometrics” is derived from the Greek words bio (life) and metric (to measure). The sole purpose of biometrics is either identifica- tion or verification. This is performed based on two unique characteristics of human; the physiological uniqueness and the behavioral uniqueness. Physi- ological uniqueness is the characteristics that people are born with, which include fingerprint, face, and iris, etc. Behavioral uniqueness is the characteristics aBstract The Gabor wavelets are employed regularly in various biometrics applications because of their biologi- cal relevance and computational properties. These wavelets have kernels similar to the 2D receptive feld profles of the mammalian cortical simple cells. They exhibit desirable characteristics of spatial locality and orientation selectivity, and are optimally localized in the space and frequency domains. Physiological, biometric systems such as face, fngerprint, and iris based human identifcation have shown great improvement in identifcation accuracies if Gabor wavelets are used for feature extraction. Moreover, some behavioral biometric systems such as speaker and gait based applications have shown more than 7% increase in identifcation accuracies. In this study, we provide a brief discussion on the origin of Gabor wavelets, then an illustration of “how to use Gabor wavelets” to extract features for a generic biometric application is discussed. We also provide an implementation pseudocode for the wavelet. It also offers an elaborate discussion on biometric applications with specifc emphasis on be- havioral biometric systems that have used Gabor wavelets. We also provide guideline for some biometric systems that have not yet applied Gabor wavelets for feature extraction. DOI: 10.4018/978-1-60566-725-6.ch006