ADAPTIVE LIGHT SOURCE

• US 20170249501A1
• Filed: 05/09/2017
• Published: 08/31/2017
• Est. Priority Date: 11/10/2015
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Van der Sijde, Arjen, Pfeffer, Nicola, Van Voorst-Vader, Quint, Martynov, Yourii, Schrama, Charles
• Granted Patent: US 10,484,616 B2
• Time in Patent Office: Days
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: G03B 2215/0567 Solid-state light source, e.g. LED, laser
• CPC Class Codes: G06T 7/586 from multiple light sources, e.g. photometric stereo
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 10/147 Details of sensors, e.g. sensor lenses fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19
• CPC Class Codes: G06V 20/10 Terrestrial scenes scenes under surveillance with static cameras G06V20/52; scenes perceived from the exterior of a vehicle G06V20/56; scenes perceived from the interior of a vehicle G06V20/59
• CPC Class Codes: G06V 20/64 Three-dimensional objects
• CPC Class Codes: G06V 40/166 using acquisition arrangements
• CPC Class Codes: G06V 40/172 Classification, e.g. identification
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A method includes capturing a first image of a scene, detecting a face in a section of the scene from the first image, and activating an infrared (IR) light source to selectively illuminate the section of the scene with IR light. The IR light source includes an array of IR light emitting diodes (LEDs). The method includes capturing a second image of the scene under selective IR lighting from the IR light source, detecting the face in the second image, and identifying a person based on the face in the second image.

Claims

1. :

A method, comprising;

capturing a first image of a scene;

detecting a face in a section of the scene from the first image;

activating an infrared (IR) light source to selectively illuminate the section of the scene with IR light, the IR light source comprising an array of IR light emitting diodes (LEDs);

capturing a second image of the scene under selective IR lighting from the IR light source;

detecting the face in the second image; and

identifying a person based on the face in the second image.

2. :

The method of claim 1, prior to said capturing the first image of the scene, further comprising activating the IR light source to uniformly illuminate the scene with IR light by driving each of the IR LEDs in the array with a first individual current.

3. :

The method of claim 2, wherein said activating the IR light source to selectively illuminate the section of the scene with IR light comprises selecting a group of IR LEDs in the array and driving each of the IR LEDs in the group with a second individual current that is greater than the first individual current.

4. :

The method of claim 3, wherein a first total current comprising the sum of the first individual currents and a second total current comprising the sum of the second individual currents are equal.

5. :

The method of claim 2, wherein said activating the IR light source to selectively illuminate the section of the scene with IR light comprises selecting a group of IR LEDs in the array and driving each of the IR LEDs in the group with a second individual current less than the first current, a first total current comprising the sum of the first individual currents being greater than a second total current comprising the sum of the second individual currents.

6. :

The method of claim 1, wherein said capturing the first image of the scene occurs under ambient lighting.

7. :

The method of claim 6, prior to said activating the IR light source to selectively illuminate the section of the scene with IR light, further comprising;

activating the IR light source to uniformly illuminate the scene with IR light capturing an intermediate image of the scene under uniform IR lighting from the IR light source;

detecting the face in the intermediate image; and

calculating an amount of IR light to illuminate the section of the scene based on brightness values of the face in the first and the intermediate images.

8. :

The method of claim 7, wherein said calculating the amount of IR light to illuminate the section of the scene is based on a difference between corresponding brightness value of the face from the first and the intermediate images.

9. :

The method of claim 1, prior to said activating the IR light source to selectively illuminate the section of the scene with IR light, further comprising;

creating a three dimensional profile of the face; and

calculating an amount of IR light to illuminate the section of the scene based on the first image and the three dimensional profile of the face.

10. :

The method of claim 1, prior to said activating the IR light source to selectively illuminate the section of the scene with IR light, further comprising;

creating a three dimensional profile of the face;

activating the IR light source to uniformly illuminate the scene with IR light capturing an intermediate image of the scene under uniform IR lighting from the IR light source;

detecting the face in the intermediate image; and

calculating an amount of IR light to illuminate the section of the scene is based brightness values of the face in the first and the intermediate images and the three dimensional profile of the face.

11. :

The method of claim 1, wherein a first LED in the array emits IR light of a different emission spectrum than IR light emitted by a second LED in the array.

12. :

The method of claim 1, wherein the array is a first array of IR LEDs, the IR light source further comprises a second array of IR LEDs, the first and the second arrays of IR LEDs illuminate a same portion or different portions of the face.

13. :

The method of claim 12, wherein the first LED in the array emits IR light of a different emission spectrum than IR light emitted by the second LED in the array.

14. :

The method of claim 1, wherein sad identifying a person based on the face in the second image comprises comparing the face in the second image against facial images in a database and finding a match.

15. :

A system, comprising;

a camera having a field of view;

an infrared (IR) light source comprising an array of IR light emitting diodes (LEDs);

nonvolatile memory storing instructions for a face detection and recognition application;

a microprocessor encoded with instructions for;

capturing, with the camera, a first image of a scene;

detecting a face in a section of the scene from the first image;

activating the IR light source to selectively illuminate the section of the scene with IR light, the IR light source comprising an array of IR light emitting diodes (LEDs);

capturing, with the camera, a second image of the scene under selective IR lighting from the IR light source;

detecting the face in the second image; and

identifying a person based on the face in the second image.

16. :

The system of claim 15, wherein the microprocessor is further encoded with instructions for, prior to said capturing the first image of the scene, activating the IR light source to uniformly illuminate the scene with IR light by driving each of the IR LEDs in the array with a first individual current.

17. :

The system of claim 16, wherein said activating the IR light source to selectively illuminate the section of the scene with IR light comprises selecting a group of IR LEDs in the array and driving each of the IR LEDs in the group with a second individual current that is greater than the first individual current.

18. :

The system of claim 17, wherein a first total current comprising the sum of the first individual currents and a second total current comprising the sum of the second individual currents are equal.

19. :

The system of claim 16, wherein said activating the IR light source to selectively illuminate the section of the scene with IR light comprises selecting a group of IR LEDs in the array and driving each of the IR LEDs in the group with a second individual current less than the first individual current, a first total current comprising the sum of the first individual currents being greater than a second total current comprising the sum of the second individual currents.

20. :

The system of claim 15, wherein said capturing the first image of the scene occurs under ambient lighting.

21. :

The system of claim 20, wherein the microprocessor is further encoded with instructions for, prior to said activating the IR light source to selectively illuminate the section of the scene with IR light;

activating the IR light source to uniformly illuminate the scene with IR light capturing an intermediate image of the scene under uniform IR lighting from the IR light source;

detecting the face in the intermediate image; and

calculating an amount of IR light to illuminate the section of the scene based on brightness values of the face in the first and the intermediate images.

22. :

The system of claim 21, wherein said calculating the amount of IR light to illuminate the section of the scene is based on a difference between corresponding brightness value of the face from the first and the intermediate images.

23. :

The system of claim 15, wherein the microprocessor is further encoded with instructions for, prior to said activating the IR light source to selectively illuminate the section of the scene with IR light;

creating a three dimensional profile of the face; and

calculating an amount of IR light to illuminate the section of the scene based on the first image and the three dimensional profile of the face.

24. :

The system of claim 15, wherein the microprocessor is further encoded with instructions for, prior to said activating the IR light source to selectively illuminate the section of the scene with IR light;

creating a three dimensional profile of the face;

activating the IR light source to uniformly illuminate the scene with IR light

capturing an intermediate image of the scene under uniform IR lighting from the IR light source;

detecting the face in the intermediate image; and

calculating an amount of IR light to illuminate the section of the scene is based brightness values of the face in the first and the intermediate images and the three dimensional profile of the face.

25. :

The system of claim 15, wherein a first LED in the array emits IR light of a different emission spectrum than IR light emitted by a second LED in the array.

26. :

The system of claim 15, wherein the array of IR LEDs is a first array of IR LEDs, the IR light source further comprises a second array of IR LEDs, the first and the second arrays of IR LEDs illuminate a same portion or different portions of the face.

27. :

The system of claim 26, wherein the first LED in the array emits IR light of a different emission spectrum than IR light emitted by the second LED in the array.

28. :

The system of claim 15, wherein sad identifying a person based on the face in the second image comprises comparing the face in the second image against facial images in a database and finding a match.

29. :

A non-transitory, computer-readable storage medium encoded with instructions executable by a microprocessor to selectively illuminate a scene, the instructions comprising;

capturing a first image of a scene;

detecting a face in a section of the scene from the first image;

activating an infrared (IR) light source to selectively illuminate the section of the scene with IR light, the IR light source comprising an array of IR light emitting diodes (LEDs);

capturing a second image of the scene under selective IR lighting from the IR light source;

detecting the face in the second image; and

identifying a person based on the face in the second image.