Methods and systems are provided for performing a biometric measurement on
an individual. A purported skin site of the individual disposed relative
to a platen is illuminated under distinct optical conditions during a
single illumination session. At least one of the optical conditions
includes illuminating the purported skin site with light at an angle
greater than a critical angle defined by an interface of the platen with
an external environment. At least another of the distinct optical
conditions includes illuminating the purported skin site with light at an
angle less than the critical angle. Light scattered from the purported
skin site is received separately for each of multiple optical conditions
to derive a multispectral image of the purported skin site.