This book discusses and generalizes ideas which are common for biometric modalities such as voice, face, iris, fingerprints, hand geometry/palm/veins, dynamic signature. The author distills the vast area of biometrics theory and application into a unified framework using biometric modalities as particular cases. This approach gives a suitable mix of theoretical development and practical uses of biometric techniques.As is usually the case, the many contributors to this field generally use disparate notations and mathematical techniques, making the material less accessible. This book presents the variety of biometric techniques based on feature extraction and classification in a common notational and mathematical framework so that the concepts may be assimilated more efficiently and the relationships among the different concepts can be better appreciated. This approach makes the book as complete and self-contained as possible by including derivations of virtually all the concepts presented. At the same time, it is attempted within this framework to make the book accessible to readers who are not interested in all the mathematical details.Hardware implementation of biometric techniques is not discussed, although the application examples give many opportunities to point out common modifications to the algorithms necessary in many applications. What the author does hope to communicate to the reader of this book is a basic understanding of the calculation structures and algorithms used for biometric techniques, and what modifications to these algorithms have to be made due to practical constraints. In this context Fundamentals of Biometrics may be used as an advanced text for a course on the subject.