1. A method of performing a biometric function, the method comprising: illuminating a small-area purported skin site of an individual with illumination light; receiving light scattered from the small-area purported skin site; generating a local feature profile from the received light, wherein the local feature profile identifies a feature of the small-area purported skin site of a type predetermined to exhibit substantial local consistency across non-overlapping skin sites of the individual; and analyzing the generated local feature profile to perform the biometric function, the biometric function selected from a group consisting of an identity function, a demographic function, and an anthropometric function, wherein analyzing the generated local feature profile comprises comparing the generated local feature profile with a reference local feature profile generated from light scattered from a small-area reference skin site of the individual that was previously captured during biometric enrollment of the individual and does not overlap with the small-area purported skin site.