FACE IMAGE PICKUP DEVICE AND METHOD

• US 20100254571A1
• Filed: 11/07/2008
• Published: 10/07/2010
• Est. Priority Date: 11/09/2007
• Status: Active Grant

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Asano, Tadashi, Fujimoto, Akira, Yoshinaga, Yukihiko, Matsuura, Yukihiro
• Granted Patent: US 8,295,559 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06V 20/635 Overlay text, e.g. embedded captions in a TV program
• CPC Class Codes: G06V 40/171 Local features and components; Facial parts eye characteristics G06V40/18; Occluding parts, e.g. glasses; Geometrical relationships

Abstract

There are provided a face image pickup device and a face image pickup method which can stably acquire a face image by appropriate illumination, and a program thereof. The face image pickup device comprises a camera which picks up an image of a face of a target person, an illumination light source which illuminates the face of the target person with near-infrared light having an arbitrary light amount, and a computer. The computer detects an area including an eye from the face image of the target person picked up by the camera. The computer measures a brightness distribution in the detected area. Thereafter, the computer controls the illumination light source so as to change the amount of near-infrared light based on the measured brightness distribution.

Claims

1. A face image pickup device comprising:

face image pickup unit which picks up an image of a face of a target person;

illumination unit which illuminates the face of the target person with near-infrared light having an arbitrary light amount;

eye area detecting means which detects an area including an eye from the face image of the target person picked up by the face image pickup unit;

brightness-distribution measuring unit which measures a brightness distribution in the area detected by the eye area detecting unit in the face image of the target person picked up by the face image pickup means; and

control unit which controls the illumination unit so as to change an amount of the near-infrared light based on the brightness distribution measured by the brightness-distribution measuring unit.

2. The face image pickup device according to claim 1, wherein the control unit calculates an average brightness in the area based on the brightness distribution, and controls the illumination unit so as to change an amount of the near-infrared light based on the calculated average brightness.

3. The face image pickup device according to claim 2, wherein the control unit determines whether or not the average brightness is out of a predetermined range, and controls the illumination unit so as to change an amount of near-infrared light upon determination that the average brightness is out of the predetermined range.

4. The face image pickup device according to claim 3, wherein the control unit controls the illumination unit so as to increase an amount of the near-infrared light upon determination that the average brightness is out of the predetermined range.

5. The face image pickup device according to claim 1, wherein the face image pickup unit includes an optical filter which is arranged on an optical axis for picking up an image of the face of the target person and which allows arbitrary long wavelength including near-infrared light to transmit.

6. The face image pickup device according to claim 5, wherein

the illumination unit includes an LED (Light Emitting Diode) emitting near-infrared light transmissive through the optical filter, and

the LED illuminates the face of the target person with near-infrared light.

7. The face image pickup device according to claim 6, wherein an amount of the near-infrared light emitted by the illumination unit is adjusted by a current value input into the LED or a duty ratio by pulse light emitting.

8. The face image pickup device according to claim 1, wherein the face image pickup unit is arranged on a top face of a steering column of a vehicle.

9. The face image pickup device according to claim 1, wherein the face image pickup unit is arranged on a top face of an instrumental panel of a vehicle.

10. The face image pickup device according to claim 1, wherein the face image pickup unit is arranged on a top face of a center console of a vehicle.

11. The face image pickup device according to claim 1, wherein the face image pickup unit is arranged in a rearview mirror of a vehicle.

12. A face image pickup method executed by a device comprising face image pickup unit which picks up an image of a face of a target person and illumination means which illuminates the face of the target person with near-infrared light having an arbitrary light amount, the method comprising:

an eye area detecting step of detecting an area including an eye from the face image of the target person picked up by the face image pickup means;

a brightness-distribution measuring step of measuring a brightness distribution in the area detected in the eye area detecting step in the face image of the target person picked up by the face image pickup means; and

a control step of controlling the illumination means so as to change an amount of the near-infrared light based on the brightness distribution measured in the brightness-distribution measuring step.

13. The face image pickup method according to claim 12, wherein in the control step, an average brightness in the area is calculated based on the brightness distribution, and the illumination unit is controlled so as to change an amount of the near-infrared light based on the calculated average brightness.

14. A Non-transitory computer-readable medium storing a program allowing a computer which includes face image pickup unit that picks up an image of a face of a target person and illumination unit that illuminates the face of the target person with near-infrared light having an arbitrary light amount to function as:

eye area detecting unit which detects an area including an eye from the face image of the target person picked up by the face image pickup unit;

brightness-distribution measuring unit which measures a brightness distribution in the area detected by the eye area detecting unit in the face image of the target person picked up by the face image pickup unit; and

control unit which controls the illumination unit so as to change an amount of the near-infrared light based on the brightness distribution measured by the brightness-distribution measuring unit.

15. The according to claim 14, wherein the control unit calculates an average brightness of area based on the brightness distribution, and controls the illumination unit so as to change an amount of the near-infrared light based on the calculated average brightness.