Method and system for biometric recognition
View Patent ↗High quality, high contrast images of an iris and the face of a person are acquired in rapid succession in either sequence by a single sensor and one or more illuminators, preferably within less than one second of each other, by changing the data acquisition settings or illumination settings between each acquisition.
1. A method for biometric acquisition, the method comprising:
determining, by a depth measurement sensor, a distance of a first image sensor from a face of an individual;
acquiring, by the first image sensor at a first time instant, an image of an iris of the individual, the iris illuminated by a light source set to output a first intensity magnitude suitable for acquiring the image of the iris at the determined distance for iris recognition; and
acquiring, by the first image sensor at a second time instant, an image of the face, the face illuminated by the light source set to output a second intensity magnitude suitable for acquiring the image of the face at the determined distance, wherein the second time instant is within a predetermined time period of the first time instant sufficient to link the image of the iris and the image of the face to the same individual.
2. The method of claim 1 , wherein determining the distance of the first image sensor from the face comprises determining at least one of a diameter of the iris or a separation distance between two eyes of the individual.
3. The method of claim 1 , further comprising performing iris recognition using the image of the iris, and performing facial recognition using the image of the face.
4. The method of claim 1 , further comprising determining an orientation of the face using the image of the face, and determining an expected orientation and location of the iris on the image of the iris using the determined orientation of the face.
5. The method of claim 1 , further comprising performing registration between the image of the iris and the image of the face.
6. The method of claim 1 , wherein the light source comprises at least one visible light illuminator and at least one infra-red light illuminator.
7. The method of claim 1 , further comprising adjusting the light source responsive to the determined distance.
8. The method of claim 1 , wherein determining the distance comprises comparing at least one of a diameter of the iris or a separation distance between two eyes of the individual, with one or more values of a reference table.
9. The method of claim 1 , further comprising adjusting, by an imaging controller, at least one of: sensor gain, sensor offset, illumination pulse width, shutter speed, focus, zoom or integration time for image acquisition, between the acquisition of the image of the iris and the acquisition of the image of the face.
10. The method of claim 1 , wherein the acquisition of at least one of the image of the iris or the image of the face occur while the individual is in motion.
11. A system for biometric acquisition, the system comprising:
a depth measurement sensor configured to determine a distance of a first image sensor from a face of an individual;
a light source; and
the first image sensor, the first image sensor configured to:
acquire, at a first time instant, an image of an iris of the individual, the iris illuminated by the light source set to output a first intensity magnitude suitable for acquiring the image of the iris at the determined distance for iris recognition; and
acquire, at a second time instant, an image of the face, the face illuminated by the light source set to output a second intensity magnitude suitable for acquiring the image of the face at the determined distance, wherein the second time instant is within a predetermined time period of the first time instant sufficient to link the image of the iris and the image of the face to the same individual.
12. The system of claim 11 , wherein the depth measurement sensor is configured to determine the distance of the first image sensor from the face by determining and using at least one of a diameter of the iris or a separation distance between two eyes of the individual.
13. The system of claim 11 , further comprising a biometric recognition processor configured to perform iris recognition using the image of the iris, and perform facial recognition using the image of the face.
14. The system of claim 11 , further comprising a processor configured to determine an orientation of the face using the image of the face, and to determine an expected orientation and location of the iris on the image of the iris using the determined orientation of the face.
15. The system of claim 11 , further comprising a processor configured to perform registration between the image of the iris and the image of the face.
16. The system of claim 11 , wherein the light source comprises at least one visible light illuminator and at least one infra-red light illuminator.
17. The system of claim 11 , wherein the light source is adjusted responsive to the determined distance.
18. The system of claim 11 , wherein the depth measurement sensor is configured to determine the distance by comparing at least one of a diameter of the iris or a separation distance between two eyes of the individual, with one or more values of a reference table.
19. The system of claim 11 , further comprising an imaging controller configured to adjust at least one of: sensor gain, sensor offset, illumination pulse width, shutter speed, focus, zoom or integration time for image acquisition, between the acquisition of the image of the iris and the acquisition of the image of the face.
20. The system of claim 11 , wherein the first imaging sensor is configured to acquire at least one of the image of the iris or the image of the face occur while the individual is in motion.