Optical biometrics imaging with films
View Patent ↗Methods and systems are provided for performing a biometric measurement on an individual. A purported skin site of the individual is illuminated under a plurality of distinct optical conditions during a single illumination session. Light scattered beneath a surface of the purported skin site is received separately for each of the plurality of distinct optical conditions. A multispectral image of the purported skin site is derived from the received light. A biometric function is performed with the derived multispectral image.
1. A biometric measurement system comprising:
a platen;
a thin film;
an illumination source disposed to illuminate a skin site positioned over the platen in a configuration in which the thin film is disposed between the platen and the skin site;
an imaging system disposed to receive light scattered from the skin site; and
a controller interfaced with the illumination source and the imaging system, the controller including:
instructions to illuminate the skin site through the thin film under a plurality of distinct optical conditions during a single illumination session;
instructions to derive an image of the skin site from light received by the imaging system with direct imaging according to the distinct optical conditions; and
instructions to perform a biometric function with the derived image.
2. The biometric measurement system recited in claim 1 wherein the plurality of distinct optical conditions comprise a plurality of different wavelengths of light emitted by the illumination source.
3. The biometric measurement system recited in claim 1 wherein the plurality of distinct optical conditions comprise a plurality of different illumination angles at which light emitted by the illumination source is directed to the skin site.
4. The biometric measurement system recited in claim 1 further comprising:
a first polarizer disposed to polarize light emitted by the illumination source;
a second polarizer disposed to polarize light received by the imaging system,
wherein the plurality of distinct optical conditions comprise distinct relative polarization conditions.
5. The biometric measurement system recited in claim 1 wherein the thin film is optically clear at a wavelength of light emitted by the illumination source.
6. The biometric measurement system recited in claim 1 wherein the thin film is positioned on the skin site.
7. The biometric measurement system recited in claim 1 wherein the instructions to illuminate the skin site through the thin film under a plurality of distinct optical conditions comprise instructions to illuminate the skin site under the plurality of distinct optical conditions sequentially.
8. The biometric measurement system recited in claim 1 wherein the instructions to illuminate the skin site through the film under a plurality of distinct optical conditions comprises instructions to illuminate the skin site further under imaging conditions substantially affected by total internal reflectance.
9. The biometric measurement system recited in claim 1 wherein the skin site is separated from the platen by a volume of an external environment.
10. The biometric measurement system recited in claim 1 wherein the thin film includes an adhesive.
11. A method of performing a biometric measurement on an individual, the method comprising:
illuminating a skin site of the individual under a plurality of distinct optical conditions, wherein the skin site is positioned over a platen in a configuration in which a thin film is disposed between the platen and the skin site;
receiving light scattered from the skin site with an imaging system using direct imaging;
deriving an image of the skin site from the received light according to the distinct optical conditions; and
performing a biometric function with the derived image.
12. The method recited in claim 11 wherein the plurality of distinct optical conditions comprise a plurality of different wavelengths of light.
13. The method recited in claim 11 wherein the plurality of distinct optical conditions comprise a plurality of different illumination angles at which light is directed to the skin site.
14. The method recited in claim 11 wherein the plurality of distinct optical conditions comprise a plurality of distinct polarization conditions.
15. The method recited in claim 11 wherein the thin film is optically clear at a wavelength of light illuminating the skin site.
16. The method recited in claim 11 wherein the thin film is positioned on the skin site.
17. The method recited in claim 11 wherein illuminating the skin site of the individual under the plurality of distinct optical conditions is performed sequentially.
18. The method recited in claim 11 wherein illuminating the skin site of the individual is further performed under imaging conditions substantially affected by total internal reflectance.
19. The method recited in claim 11 wherein the skin site is separated from the platen by a volume of an external environment.
20. The method recited in claim 11 wherein the thin film includes an adhesive.