Methods and systems are provided for combining total-internal-reflectance and
tissue imaging to perform biometric functions. The
system may include an illumination source, a platen, a
light detector, an optical
train, and a computational unit. The platen is disposed to make contact with a
skin site of an individual. The optical
train is disposed to provide optical paths between the illumination source and the platen, and between the platen and the
light detector. The combination of the illumination source and optical
train provides illumination to the platen under multispectral conditions. The computational unit is interfaced with the
light detector and has instructions to generate a total-internal-reflectance image of the
skin site from a first portion of light received from the
skin site, and to generate a tissue image of the skin site from a second portion of light received from the skin site.