Method and device for recognition of natural skin during contact-free biometric identification of a person

Abstract

A contact-free biometric identification apparatus includes a housing, a first light-emitting diode (LED) positioned in the housing having a first predetermined wavelength to illuminate a portion of skin, a second LED positioned in the housing having a second predetermined wavelength to illuminate the portion of skin, an irradiation location outside of the housing and defined by illumination from the first and second LED on the portion of skin, a detector at a predetermined position in the housing for detecting a fraction of the first and second LED light scattered from the irradiation. location and a processing unit that employs a scatter function to determine the presence of live skin based on a correspondence of the detected light to stored data of optical properties of skin.

1 . A contact-free biometric identification apparatus comprising:
 a housing;   a first light-emitting diode (LED) positioned in the housing and having a first predetermined wavelength to illuminate a portion of skin;   a second LED positioned in the housing and having a second predetermined wavelength to illuminate the portion of skin;   an irradiation location that is outside of the housing and is defined by illumination from the first and second LED on the portion of skin;   a detector that is at a predetermined position in the housing and detects a fraction of the first and second LED light scattered from the irradiation location; and   a processing unit that employs a scatter function to determine the presence of live skin based on a correspondence of the detected light to stored data of optical properties of skin.   
     
     
         2 . The device of  claim 1  further comprising:
 another detector that is at another predetermined position in the housing and detects another fraction of the first and second LED light scattered from the irradiation location; and 
 wherein the processing unit uses the detected light and the detected another light to determine the presence of live skin based on another correspondence to the stored data of optical properties of skin. 
 
     
     
         3 . The device of  claim 1  wherein the detector is a camera. 
     
     
         4 . The device of  claim 1  wherein the scatter function compares different limit and magnitude values of the first predetermined wavelength and the second predetermined wavelength in the detected light to determine whether there is correspondence to stored data of optical properties of skin. 
     
     
         5 . A method performed by a contact-free biometric identification apparatus, the method comprising:
 illuminating a portion of skin at a first predetermined wavelength by a first light-emitting diode (LED) positioned in a housing;   illuminating the portion of skin at a second predetermined wavelength by a second LED positioned in the housing;   detecting, with a detector that is at a predetermined position in the housing, a fraction of the first and second LED light scattered from an irradiation location on the portion of skin outside of the housing; and   employing a scatter function by a processing unit to determine the presence of live skin based on a correspondence of the detected light to stored data of optical material properties of skin.   
     
     
         6 . The method of  claim 5  further comprising:
 detecting, by another detector that is at another predetermined position in the housing, another fraction of the first and second LED light scattered from the irradiation location; and 
 determining by the processing unit using the detected light and the detected another light to determine the presence of live skin based on another correspondence to the stored data of optical material properties of skin. 
 
     
     
         7 . The method of  claim 5  wherein the detector is a camera. 
     
     
         8 . The method of  claim 5  wherein the scatter function compares different limit and magnitude values of the first predetermined wavelength component and the second predetermined wavelength component of the detected fraction of light scattered to determine whether there is correspondence to stored data of optical material properties of live skin. 
     
     
         9 . A method performed by a device providing contact-free biometric identification, the method comprising:
 illuminating by a first light-emitting diode (LED) a portion of skin, wherein the first LED provides a first predetermined wavelength of visible light;   illuminating, subsequently, by a second LED the portion of skin, wherein the second LED provides a second predetermined wavelength of visible light;   detecting with a detector at a detection location a fraction of scattered light from an irradiation location on the portion of skin, wherein the fraction of scattered light is generated based on the illuminating by the first LED and second LED;   determining by a processing unit correspondence of the fraction of scattered light to stored data of optical material properties of live skin, wherein the determining is based on a scatter function comparing different limit and magnitude values of the first predetermined wavelength of visible light component and the second predetermined wavelength of visible light component; and   wherein the irradiation location is at a different location from the detection location.   
     
     
         10 . A contact-free biometric identification apparatus comprising:
 a housing;   a first light-emitting diode (LED) that has a first predetermined wavelength and is positioned in the housing to illuminate a portion of skin;   a second LED that has a second predetermined wavelength and is positioned in the housing to illuminate the portion of skin;   an irradiation location that is outside of the housing and is defined by illumination from the first and second LED on the portion of skin;   a detector positioned in the housing to detect a fraction of the first and second LED light scattered from the irradiation location; and   a processing unit that employs a scatter function to determine the presence of live skin based on a correspondence of the detected light to stored data of optical properties of skin.