Encoded binary liveness detector

摘要

A device for detecting the presence of human skin including an illuminator source for providing a first encoded IR band and a second encoded IR band. The first encoded IR band is capable of being reflected from skin and the second encoded IR band is capable of being absorbed by skin. A detector receives the first and second encoded IR band after the bands have contacted the skin and provides an encoded signal indicating the presence or absence of each of the first and second IR bands. A processing unit decodes and processes the signal and indicates the presence of skin when the first IR band is present and the second IR band is absent.