Adaptive light source
A method according to embodiments of the invention includes creating a three-dimensional profile of a scene, calculating a relative amount of light for each portion of the scene based on the three-dimensional profile, and activating a light source to provide a first amount of light to a first portion of the scene, and a second amount of light to a second portion of the scene. The first amount and the second amount are different. The first amount and the second amount are determined by calculating a relative amount of light for each portion of the scene.
1. A system, comprising:
an array of light-emitting diodes (LEDs);
a camera coupled to the array of LEDs, the camera having a field of view that includes a scene;
a 3D sensor;
at least one hardware-based processor coupled to the camera, the array of LEDs, and the 3D sensor; and
memory, including instructions that, when executed by the at least one hardware-based processor, cause the at least one hardware-based processor to execute instructions, the instructions comprising:
for portions of the scene that correspond to individual LEDs in the array of LEDs, using the 3D sensor to determine a distance from the array of LEDs to each portion of the scene;
calculating a relative amount of light for each portion of the scene based at least in part on the corresponding determined distance from the array of LEDs to the portion;
determining, from the calculated relative amounts of light, that a first portion of the scene and a second portion of the scene receive different amounts of light;
providing a first amount of current, based on the calculated relative amounts of light, to a first LED of the array of LEDs to illuminate the first portion of the scene;
providing a second amount of current, different from the first amount of current and based on the calculated relative amounts of light, to a second LED of the array of LEDs to illuminate the second portion of the scene;
capturing, with the camera, a first image of the scene under ambient lighting;
capturing, with the camera, a second image of the scene while illuminating the scene with a first amount of light;
subtracting pixel brightness values of the first image from respective pixel brightness values of the second image to form difference values;
scaling the difference values to determine an exposure level; and
capturing, with the camera, a third image of the scene using the determined exposure level.
2. The system of claim 1 , wherein capturing the first image of the scene under the ambient lighting comprises capturing the first image of the scene while the array of LEDs is unpowered.
3. The system of claim 1 , wherein illuminating the scene with the first amount of light comprises providing a same amount of current to each LED of the array of LEDs.
4. The system of claim 1 , wherein:
the second image of the scene is captured before determining the distances from the source to the portions of the scene;
the distances from the source to the portions of the scene are determined based in part on at least one of the first image of the scene or the second image of the scene; and
calculating the relative amount of light for each portion of the scene comprises determining and comparing brightness values of the first image and the second image for each portion of the scene, to reduce overexposure of the respective portion of the scene.
5. The system of claim 1 , wherein:
the second image of the scene is captured after determining the distances from the source to the portions of the scene;
the distances from the source to the portions of the scene are determined based in part on the first image of the scene; and
calculating the relative amount of light for each portion of the scene comprises determining and comparing brightness values of the first image and the second image for each portion of the scene to reduce overexposure of the respective portion of the scene.
6. The system of claim 1 , wherein the instructions further comprise capturing, with the camera, a third image of the scene while providing the first amount of current to the first LED of the array of LEDs to illuminate the first portion of the scene and providing the second amount of current to the second LED of the array of LEDs to illuminate the second portion of the scene.
7. The system of claim 1 , wherein:
the first LED of the array of LEDs is configured to emit white light having a first emission spectrum; and
the second LED of the array of LEDs is configured to emit white light having a second emission spectrum different from the first emission spectrum.
8. The system of claim 1 , wherein:
the array of LEDs is a first array of LEDs; and
the first array of LEDs and a second array of LEDs are arranged to illuminate one or more same portions of the scene.
9. The system of claim 8 , wherein:
the first array of LEDs is configured to emit light having a first emission spectrum; and
the second array of LEDs is configured to emit light having a second emission spectrum different from the first emission spectrum.
10. A method, comprising:
for portions of a scene that correspond to individual light emitting diodes (LEDs) in an array of LEDs, determining a distance from the array of LEDs to each portion of the scene;
calculating a relative amount of light for each portion of the scene based at least in part on the corresponding determined distance from the array of LEDs to the portion;
determining, from the calculated relative amounts of light, that a first portion of the scene and a second portion of the scene receive different amounts of light;
providing a first amount of current, based on the calculated relative amounts of light, to a first LED of the array of LEDs to illuminate the first portion of the scene; and
providing a second amount of current, different from the first amount of current and based on the calculated relative amounts of light, to a second LED of the array of LEDs to illuminate the second portion of the scene;
capturing, with a camera having a field of view that includes the scene, a first image of the scene under ambient lighting;
capturing, with the camera, a second image of the scene while illuminating the scene, with the array of LEDs, with a first amount of light;
subtracting pixel brightness values of the first image from respective pixel brightness values of the second image to form difference values;
scaling the difference values to determine an exposure level; and
capturing, with the camera, a third image of the scene using the determined exposure level.
11. The method of claim 10 , further comprising: capturing, with a camera having a field of view that includes the scene, a third image of the scene while providing the first amount of current to the first LED of the array of LEDs to illuminate the first portion of the scene and providing the second amount of current to the second LED of the array of LEDs to illuminate the second portion of the scene.
12. A system, comprising:
an array of light-emitting diodes (LEDs);
a camera coupled to the array of LEDs, the camera having a field of view that includes a scene; and
at least one hardware-based processor coupled to the camera; and
memory, including instructions that, when executed by the at least one hardware-based processor, cause the at least one hardware-based processor to execute instructions, the instructions comprising:
capturing, with the camera, a first image of the scene under ambient lighting;
capturing, with the camera, a second image of the scene while illuminating the scene with a first amount of light;
for portions of the scene that correspond to individual LEDs in the array, determining, based in part on at least one of the first image of the scene or the second image of the scene, a distance from the array of LEDs to each portion of the scene;
calculating, by determining and comparing brightness values of the first image and the second image for each portion of the scene to reduce overexposure of the respective portion of the scene, a relative amount of light for each portion of the scene based at least in part on the corresponding determined distance from the array of LEDs to the portion;
determining, from the calculated relative amounts of light, that a first portion of the scene and a second portion of the scene receive different amounts of light;
providing a first amount of current, based on the calculated relative amounts of light, to a first LED of the array of LEDs to illuminate the first portion of the scene; and
providing a second amount of current, different from the first amount of current and based on the calculated relative amounts of light, to a second LED of the array of LEDs to illuminate the second portion of the scene.
13. The system of claim 12 , wherein:
the first LED of the array of LEDs is configured to emit white light having a first emission spectrum; and
the second LED of the array of LEDs is configured to emit white light having a second emission spectrum different from the first emission spectrum.