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 method, comprising:
capturing a first image of a scene under ambient lighting;
illuminating the scene with a first amount of light from a light source that includes an array of light emitting diodes (LEDs);
capturing a second image of the scene while illuminating the scene with the first amount of light;
for portions of the scene that correspond to individual LEDs in the array, determining a distance from the light source to each portion;
calculating a relative amount of light for each portion of the scene based on the first image, the second image, and the corresponding determined distance from the light source 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 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; and
capturing a final image of the scene while illuminating the first portion of the scene with light from the first LED and illuminating the second portion of the scene with light from the second LED.
2. The method of claim 1 , wherein the first amount of light from the light source is uniform such that all portions of the scene are illuminated with a known illumination profile and/or is provided in a torch mode of the light source.
3. The method 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 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.
4. The method 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 on basis of based 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.
5. The method of claim 1 , wherein:
the scene corresponds to an image viewed by a camera lens;
the method further comprises receiving a command to zoom in;
the first portion of the scene is closer to a center of the scene than the second portion; and
the first amount of current is greater than the second amount of current.
6. The method of claim 1 , wherein:
the scene corresponds to an image viewed by a camera lens;
the method further comprises receiving a command to zoom out;
the first portion of the scene is closer to an edge of the scene than the second portion; and
the first amount of current is greater than the second amount of current.
7. The method of claim 1 , wherein the first LED in the array emits white light of a different emission spectrum than white light emitted by the second LED in the array.
8. The method 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 illuminate one or more same portions of the scene.
9. The method of claim 8 , wherein the first array of LEDs emits light of a different emission spectrum than the second array of LEDs.
10. A structure, comprising:
a camera having a field of view;
a light source comprising an array of light emitting diodes (LEDs); and
a microprocessor encoded with instructions for:
capturing a first image of the field of view under ambient lighting;
illuminating the field of view with a first amount of light from the light source;
capturing a second image of the field of view while illuminating the field of view with the first amount of light;
for portions of the field of view that correspond to individual LEDs in the array, determining a distance from the light source to each portion;
calculating a relative amount of light for each portion of the field of view based on the first image, the second image, and the corresponding determined distance from the light source to the portion;
determining, from the calculated relative amounts of light, that a first portion of the field of view and a second portion of the field of view 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 field of view;
providing a second amount of current, different from the first amount 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 field of view; and
capturing a final image of the field of view while illuminating the first portion of the field of view with light from the first LED and illuminating the second portion of the field of view with light from the second LED.
11. The method of claim 1 , wherein the light array of LEDs is turned off when capturing the first image under the ambient lighting.
12. The method of claim 1 , wherein the first amount of current and the second amount of current are configured to reduce overexposure of objects in a foreground of the scene.
13. The method of claim 9 , wherein:
the first array of LEDs emits white light with a first color temperature;
the second array of LEDs emits white light with a second color temperature different than the first color temperature; and
the method further comprises:
calculating a first current for providing a first amount of light of the first color temperature and calculating a second current for providing a second amount of light of the second color temperature for providing a defined color temperature for each portion of the scene; and
activating the first array of LEDs by providing the first current and activating the second array of LEDs by providing the second current such that a sum of light provided by the first array of LEDs and the second array of LEDs provides the defined color temperature for each portion of the scene.