Although there are many books on biometrics, most are limited to a single branch. This book covers four branches of biometrics: speaker identification, fingerprint recognition, face recognition, and iris recognition. It describes classic approaches as well as the latest designs in biometric technologies and systems, including facial recognition. The book considers the use of biometrics in security, intelligence, law enforcement, and e-commerce applications. It includes several experiments and Matlab (R) code for all experiments.