Living body detection device, living body detection method, and recording medium

Abstract

A living body detection device (1) includes: an image acquisition unit (171), a determination unit (173) and a detection unit (174). The image acquisition unit (171) acquires a first image in which a subject irradiated by light in a first wavelength range is imaged, and a second image in which the subject irradiated by light in a second wavelength range is imaged, the second wavelength range being different from the first wavelength range. The determination unit (173) determines whether a relation expressed by luminance of the subject imaged in the first image and luminance of the subject imaged in the second image is a relation exhibited by a living body. The detection unit (174) detects that the subject is a living body in a case where the determination unit (173) has determined that it is the relation exhibited by the living body.

1 - 13 . (canceled) 
     
     
         14 . A living body detection device comprising:
 an image acquisition unit that acquires a first image in which a subject irradiated by light in a first wavelength range is imaged, and a second image in which the subject irradiated by light in a second wavelength range is imaged, the second wavelength range being different from the first wavelength range;   a determination unit that determines whether a relation expressed by luminance of the subject imaged in the first image and luminance of the subject imaged in the second image is a relation exhibited by a living body; and   a detection unit that detects that the subject is a living body in a case where the determination unit has determined that it is the relation exhibited by the living body.   
     
     
         15 . The living body detection device according to  claim 14 , comprising:
 an illumination unit that emits light in the first wavelength range and light in the second wavelength range at the subject;   an imaging unit that captures the first image and the second image;   an imaging control unit that synchronizes emission of the light in the first wavelength range by the illumination unit and capture of the first image by the imaging unit, and synchronizes emission of the light in the second wavelength range by the illumination unit and capture of the second image by the imaging unit.   
     
     
         16 . The living body detection device according to  claim 15 ,
 wherein the illumination unit includes a light source of an infrared LED emitting the light in the first wavelength range and a light source of an infrared LED emitting the light in the second wavelength range, and   the imaging unit is constituted by one infrared camera that captures the first image and the second image.   
     
     
         17 . The living body detection device according to  claim 14 ,
 wherein the light in the first wavelength range is light in a wavelength range such that luminance of a living body in an image irradiated by the light is equivalent to luminance of a fake living body in an image irradiated by the light; and   the light in the second wavelength range is light in a wavelength range such that luminance of a living body in an image irradiated by the light differs by at least 20 percent with luminance of a fake living body in an image irradiated by the light.   
     
     
         18 . The living body detection device according to  claim 14 ,
 wherein the image acquisition unit further acquires a third image in which the subject irradiated by light in a third wavelength range is imaged, the third wavelength range being different from the first wavelength range and the second wavelength range, and   the determination unit determines whether a relation exhibited by luminance of the subject imaged in the first image, luminance of the subject imaged in the second image and luminance of the subject imaged in the third image is a relation exhibited by a living body.   
     
     
         19 . The living body detection device according to  claim 18 ,
 wherein the first wavelength range is around 1180 nm, the second wavelength range is around 1280 nm, and the third wavelength range is around 1500 nm, and   the determination unit determines it is the relation exhibited by the living body, in the case of a relation in which luminance of the subject imaged in the second image is greater by a predetermined ratio than luminance of the subject imaged in the first image and luminance of the subject imaged in the third image.   
     
     
         20 . The living body detection device according to  claim 19 , comprising:
 a face detection unit that detects a face region of a person from each image acquired by the image acquisition unit,   wherein the determination unit determines it is the relation exhibited by the living body, in a case of a relation in which luminance of the face region imaged in the second image is greater by a predetermined ratio than luminance of the face region imaged in the first image and luminance of the face region imaged in the third image.   
     
     
         21 . The living body detection device according to  claim 20 ,
 wherein the face detection unit detects a characteristic region from the face region, and   the determination unit determines it is the relation exhibited by the living body, in a case of a relation in which luminance of the characteristic region imaged in the second image is greater by a predetermined ratio than luminance of the characteristic region imaged in the first image and luminance of the characteristic region imaged in the third image.   
     
     
         22 . The living body detection device according to  claim 14 , further comprising:
 a notification unit that gives notice that the subject is not a living body in a case where the detection unit has detected that the subject is not a living body.   
     
     
         23 . The living body detection device according to  claim 14 , wherein the living body is skin. 
     
     
         24 . The living body detection device according to  claim 17 , wherein the fake living body is constituted with silicone resin. 
     
     
         25 . A living body detection method comprising:
 an image acquisition step of acquiring a first image in which a subject irradiated by light in a first wavelength range is imaged, and a second image in which the subject irradiated by light in a second wavelength range is imaged, the second wavelength range being different from the first wavelength range;   a determination step of determining whether a relation expressed by luminance of the subject imaged in the first image and luminance of the subject imaged in the second image is a relation exhibited by a living body; and   a detection step of detecting that the subject is a living body in a case where the determination unit has determined that it is the relation exhibited by the living body.   
     
     
         26 . A non-transitory recording medium that stores a program that causes a computer to function as:
 an image acquisition unit that acquires a first image in which a subject irradiated by light in a first wavelength range is imaged, and a second image in which the subject irradiated by light in a second wavelength range is imaged, the second wavelength range being different from the first wavelength range;   a determination unit that determines whether a relation expressed by luminance of the subject imaged in the first image and luminance of the subject imaged in the second image is a relation exhibited by a living body; and
 a detection unit that detects that the subject is a living body in a case where the determination unit has determined that it is the relation exhibited by the living body.