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US 2017/0249501 A1Published application
Adaptive light source
AssigneeKoninklijke Philips N.V.
InventorsArjen Van der Sijde, Nicola Pfeffer, Quint Van Voorst-Vader, Yourii Martynov, Charles Schrama
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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.
Claims29
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.
5 more elements
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.
2 more elements
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.
1 more element
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.
3 more elements
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.
9 more elements
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.
2 more elements
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.
1 more element
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.
4 more elements
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.
5 more elements