JP-7854596-B2 - Biometric authentication systems and biometric authentication methods

Inventors

• 宍戸 三四郎
• 町田 真一

Assignees

• パナソニックＩＰマネジメント株式会社

Dates

Publication Date

20260507

Application Date

20211203

Priority Date

20201223

Claims (19)

1. A first image acquisition unit acquires a visible light image obtained by capturing the first reflected light generated by the reflection of visible light from the skin of a subject, A second image acquisition unit acquires a first infrared image obtained by capturing a second reflected light having a wavelength range including a first wavelength, which is generated by the reflection of a first infrared light irradiated onto the skin by the skin, The system includes a determination unit that determines whether the subject is a living organism based on a comparison of the visible light image and the first infrared image, and outputs the result of the determination. Biometric authentication system.
2. The system further includes a first authentication unit that performs first personal authentication of the subject based on the visible light image and outputs the result of the first personal authentication. The biometric authentication system according to claim 1.
3. If the determination unit determines that the subject is not a living organism, the first authentication unit does not perform the first personal authentication of the subject. The biometric authentication system according to claim 2.
4. The system further includes a second authentication unit that performs second personal authentication of the subject based on the first infrared image and outputs the result of the second personal authentication. The biometric authentication system according to claim 2 or 3.
5. A storage device that stores information for performing the first personal authentication and the second personal authentication, The system further includes an information building unit that links the information relating to the result of the first personal authentication and the information relating to the result of the second personal authentication and stores them in the storage device. The biometric authentication system according to claim 4.
6. The determination unit determines whether or not the subject is a living organism by comparing the contrast value based on the visible light image with the contrast value based on the first infrared image. A biometric authentication system according to any one of claims 1 to 5.
7. The imaging unit further includes a first imaging device for capturing the visible light image and a second imaging device for capturing the first infrared image, The first image acquisition unit acquires the visible light image from the first imaging device, The second image acquisition unit acquires the first infrared image from the second imaging device. A biometric authentication system according to any one of claims 1 to 6.
8. The imaging unit further includes a third imaging device that captures the visible light image and the first infrared image, The first image acquisition unit acquires the visible light image from the third imaging device, The second image acquisition unit acquires the first infrared image from the third imaging device. A biometric authentication system according to any one of claims 1 to 6.
9. The third imaging device includes a first photoelectric conversion layer having spectral sensitivity to the wavelength range of visible light and the first wavelength. The biometric authentication system according to claim 8.
10. The third imaging device includes a second photoelectric conversion layer having spectral sensitivity over the entire wavelength range of visible light. The biometric authentication system according to claim 9.
11. The lighting device further comprises irradiating the subject with the first infrared light. A biometric authentication system according to any one of claims 7 to 10.
12. The system further includes a timing control unit that controls the timing of imaging by the imaging unit and the timing of illumination by the illumination device. The biometric authentication system according to claim 11.
13. The system further includes a third image acquisition unit that acquires a second infrared image obtained by capturing a third reflected light having a wavelength range including a second wavelength different from the first wavelength, which is generated by the reflection of a second infrared light irradiated onto the skin by the skin, The determination unit determines whether or not the subject is a living organism based on the visible light image, the first infrared image, and the second infrared image. A biometric authentication system according to any one of claims 1 to 12.
14. The determination unit generates a difference infrared image from the first infrared image and the second infrared image, and determines whether or not the subject is a living organism based on the difference infrared image and the visible light image. The biometric authentication system according to claim 13.
15. The first wavelength is 1100 nm or less. A biometric authentication system according to any one of claims 1 to 14.
16. The first wavelength is 1200 nm or greater. A biometric authentication system according to any one of claims 1 to 14.
17. The first wavelength is between 1350 nm and 1450 nm. A biometric authentication system according to any one of claims 1 to 14.
18. The subject in question is a human face. A biometric authentication system according to any one of claims 1 to 17.
19. A visible light image is obtained by capturing the first reflected light generated by the reflection of visible light from the skin of the subject, A first infrared image is obtained by capturing a second reflected light having a wavelength range including a first wavelength, which is generated by the reflection of infrared light irradiated onto the skin by the skin, The process includes determining whether the subject is a living organism based on a comparison between the visible light image and the first infrared image, and outputting the result of the determination. Biometric authentication methods.

Description

This disclosure relates to a biometric authentication system and a biometric authentication method. In recent years, the importance of biometric authentication for personal identification has been increasing in areas such as office entry and exit, immigration control, payments at financial institutions or via smartphones, and public surveillance cameras. The accuracy of personal authentication has also improved through the use of machine learning, leading to the accumulation of large databases and algorithm modifications. However, impersonation by unauthorized individuals remains a challenge in biometric authentication. For example, Patent Document 1 discloses a detection device for detecting items used as disguises for impersonation. In biometric authentication, there is a need for improved authentication accuracy to combat impersonation and other theft, as well as for miniaturization of biometric authentication devices. Japanese Patent Publication No. 2017-228316 Holger Steiner, “Active Multispectral SWIR Imaging for Reliable Skin Detection and Face Verification”, Cuvillier Verlag, January 10, 2017, pp. 13-14 Figure 1 is a diagram illustrating the overview of the impersonation detection method used by the biometric authentication system according to Embodiment 1.Figure 2 is a block diagram showing the functional configuration of the biometric authentication system according to Embodiment 1.Figure 3 shows examples of the visible light image and the first infrared image to be compared in the determination unit according to Embodiment 1.Figure 4 schematically illustrates the light reflection characteristics in living organisms.Figure 5 shows an example of the reflectance ratio of visible light incident on human skin.Figure 6 shows the NK spectrum of liquid water.Figure 7 shows images of a human face captured at different wavelengths.Figure 8 shows the wavelength dependence of light reflectance for different skin tones.Figure 9 shows the solar spectrum on the ground.Figure 10 is a magnified view of a portion of the solar spectrum shown in Figure 9.Figure 11 is a magnified view of another portion of the solar spectrum shown in Figure 9.Figure 12 is a flowchart showing an example of the operation of the biometric authentication system according to Embodiment 1.Figure 13 is a diagram illustrating the impersonation detection method used by the biometric authentication system according to Embodiment 1, in cases where impersonation is not occurring.Figure 14 is a block diagram showing the functional configuration of a biometric authentication system according to a modified example of Embodiment 1.Figure 15 shows an exemplary configuration of a third imaging device according to a modified example of Embodiment 1.Figure 16 is a schematic cross-sectional view showing the cross-sectional structure of a pixel in a third imaging device according to a modified example of Embodiment 1.Figure 17 is a schematic diagram showing an example of a spectral sensitivity curve of a pixel according to a modified example of Embodiment 1.Figure 18 is a schematic cross-sectional view showing the cross-sectional structure of another pixel in the third imaging device according to a modified example of Embodiment 1.Figure 19 is a schematic cross-sectional view showing the cross-sectional structure of yet another pixel of the third imaging device according to a modified example of Embodiment 1.Figure 20 is a schematic diagram showing an example of a spectral sensitivity curve of yet another pixel according to a modified embodiment of the first embodiment.Figure 21 is a block diagram showing the functional configuration of the biometric authentication system according to Embodiment 2.Figure 22 is a flowchart showing an example of the operation of the biometric authentication system according to Embodiment 2.Figure 23 is a block diagram showing the functional configuration of a biometric authentication system according to a modified example of Embodiment 2.Figure 24 is a schematic cross-sectional view showing the cross-sectional structure of a pixel in a fifth imaging device according to a modified example of Embodiment 2.Figure 25 is a schematic diagram showing an example of a spectral sensitivity curve of a pixel according to a modified example of Embodiment 2. (Knowledge that led to one aspect of this disclosure) In recent years, biometric authentication methods such as facial recognition using visible light images have seen improved authentication rates due to advancements in machine learning algorithms and the availability of large databases of images from around the world or acquired independently. On the other hand, biometric authentication using images of a subject presents challenges such as fraudulent authentication by a third party impersonating the person, for example, using printed images of the person, images of the person displayed on the screen of a smartphone or tablet, or 3D masks made of paper or silicone rubber. To address