Face recognition is a growing-up branch of pattern recognition in the context
of image and vision. Conferences have arisen and brand new technologies have been
coming to light providing more and more accurate recognition rates. But what is face
recognition? The problem statement could be formulated this way: “Given still or video
images of a scene, identify or verify one or more persons in the scene using a stored
database of faces” [1]. Face recognition branch is core inasmuch the applications
involving recognition algorithms for human face are aimed at different applications
such as biometrics, authentication, identification of suspects. This chapter offers an
overview of what are similarity and similarity measures.
Keywords: Similarity, similarity measure, metric, similarity function, face
recognition.
