Proximity object tracker

1. An electronic system comprising:

an image sensor having a field of view of a first area;

an illumination source that is configured to illuminate a second area, the second area intersecting the first area to define (a) an intersection region illuminated by the illumination source and within the field of view of the image sensor and (b) a non-intersection region not illuminated by the illumination source and within the field of view of the image sensor; and

a processing unit configured to perform operations comprising:

receiving an image from the image sensor;

analyzing the image to detect an object within the intersection region and exclude objects within the non-intersection region; and

determining user input based on the object detected within the intersection region, wherein the user input is determined based on a mapped position of the detected object.

2. The electronic system of claim 1 , wherein the image sensor is located on a first side of a surface of a display screen, and wherein the field of view of the first area is in front of the display screen.

3. The electronic system of claim 2 , wherein the illumination source is configured to illuminate the second area in front of the display screen intersecting the first area in front of the display screen to define the intersection region.

4. The electronic system of claim 2 , wherein the illumination source and the image sensor are positioned such that the intersection region is within six inches from the display screen.

5. The electronic system of claim 2 , wherein the object is a finger and the user input comprises a depth of the finger in relation to the display screen.

6. The electronic system of claim 1 , wherein the operation of determining the user input based on the object detected within the intersection region comprises:

mapping a position of the object detected within the intersection region to a cursor of a user interface.

7. The electronic system of claim 1 , wherein the processing unit is further configured to perform operations comprising:

controlling an application based on the determined user input.

8. The electronic system of claim 7 , wherein controlling the application based on the determined user input comprises moving a cursor from a first cursor position to a second cursor position based on the determined user input.

9. The electronic system of claim 1 , wherein analyzing the image captured by the image sensor to detect the object within the intersection region comprises:

comparing pixels of the image to a brightness threshold to produce a binary image, wherein pixels in the binary image indicate whether or not the corresponding pixels in the image captured by the image sensor meet the brightness threshold; and

determining a position of the object in the binary image.

10. The electronic system of claim 1 , further comprising multiple illumination sources configured to illuminate in sequence with images captured by one or more image sensors in an alternating pattern with the illumination.

11. A method for determining a user input, comprising:

receiving an image from an image sensor, the image sensor having a field of view of a first area; and

illuminating, via an illumination source, a second area intersecting the first area to define (a) an intersection region illuminated by the illumination source and within the field of view of the image sensor and (b) a non-intersection region not illuminated by the illumination source and within the field of view of the image sensor;

analyzing the image to detect an object within the intersection region and exclude objects within the non-intersection region; and

determining user input based on the object detected within the intersection region, wherein the user input is determined based on a mapped position of the detected object.

12. The method of claim 11 , wherein the image sensor is located on a first side of a surface of a display screen, and wherein the field of view of the first area is in front of the display screen.

13. The method of claim 12 , wherein the illuminating comprises illuminating the second area in front of the display screen intersecting the first area in front of the display screen to define the intersection region.

14. The method of claim 12 , wherein the illumination source and the image sensor are positioned such that the intersection region is within six inches from the display screen.

15. The method of claim 12 , wherein the object is a finger and the user input comprises a depth of the finger in relation to the display screen.

16. The method of claim 11 , wherein the determining comprises mapping a position of the object detected within the intersection region to a cursor of a user interface.

17. The method of claim 11 , further comprising controlling an application based on the determined user input.

18. The method of claim 17 , wherein controlling the application based on the determined user input comprises moving a cursor from a first cursor position to a second cursor position based on the determined user input.

19. The method of claim 11 , wherein analyzing the image captured by the image sensor to detect the object within the intersection region comprises:

comparing pixels of the image to a brightness threshold to produce a binary image, wherein pixels in the binary image indicate whether or not the corresponding pixels in the image captured by the image sensor meet the brightness threshold; and

determining a position of the object in the binary image.

20. The method of claim 11 , further comprising illuminating, via multiple illumination sources, in sequence with images captured by one or more image sensors in an alternating pattern with the illumination.

21. An apparatus for determining a user input, comprising:

means for receiving an image from an image sensor, the image sensor having a field of view of a first area; and

means for illuminating a second area intersecting the first area to define (a) an intersection region illuminated by the illuminating means and within the field of view of the image sensor and (b) a non-intersection region not illuminated by the illuminating means and within the field of view of the image sensor;

means for analyzing the image to detect an object within the intersection region and exclude objects within the non-intersection region; and

means for determining user input based on the object detected within the intersection region, wherein the user input is determined based on a mapped position of the detected object.

22. The apparatus of claim 21 , wherein the image sensor is located on a first side of a surface of a display screen, and wherein the field of view of the first area is in front of the display screen.

23. The apparatus of claim 22 , wherein the means for illuminating comprises means for illuminating the second area in front of the display screen intersecting the first area in front of the display screen to define the intersection region.

24. The apparatus of claim 21 , wherein the means for analyzing the image captured by the image sensor to detect the object within the intersection region comprises:

means for comparing pixels of the image to a brightness threshold to produce a binary image, wherein pixels in the binary image indicate whether or not the corresponding pixels in the image captured by the image sensor meet the brightness threshold; and

means for determining a position of the object in the binary image.

25. A non-transitory storage medium comprising processor-readable instructions configured to cause a processor to:

receive an image from an image sensor, the image sensor having a field of view of a first area; and

illuminate, via an illumination source, a second area intersecting the first area to define (a) an intersection region illuminated by the illumination source and within the field of view of the image sensor and (b) a non-intersection region not illuminated by the illumination source and within the field of view of the image sensor;

analyze the image to detect an object within the intersection region and exclude objects within the non-intersection region; and

determine user input based on the object detected within the intersection region, wherein the user input is determined based on a mapped position of the detected object.

26. The non-transitory storage medium of claim 25 , wherein the image sensor is located on a first side of a surface of a display screen, and wherein the field of view of the first area is in front of the display screen.

27. The non-transitory storage medium of claim 26 , wherein the illuminating comprises illuminating the second area in front of the display screen intersecting the first area in front of the display screen to define the intersection region.

28. The non-transitory storage medium of claim 26 , wherein the object is a finger and the user input comprises a depth of the finger in relation to the display screen.

29. The non-transitory storage medium of claim 25 , wherein the determining comprises mapping a position of the object detected within the intersection region to a cursor of a user interface.

30. The non-transitory storage medium of claim 25 , wherein the analyzing the image captured by the image sensor to detect the object within the intersection region comprises:

comparing pixels of the image to a brightness threshold to produce a binary image, wherein pixels in the binary image indicate whether or not the corresponding pixels in the image captured by the image sensor meet the brightness threshold; and

determining a position of the object in the binary image.