Touchless input

1. A method of receiving user input, the method comprising:

receiving a series of depth maps imaging a scene, each depth map including a plurality of pixels, each of the plurality of pixels defining a depth of a surface imaged by that pixel;

identifying a set of nonstatic pixels having a shallowest depth within the series of depth maps; and

mapping a position of the set of nonstatic pixels to a cursor position.

2. The method of claim 1 , where the set of nonstatic pixels includes a plurality of contiguous pixels.

3. The method of claim 1 , where the set of nonstatic pixels includes one pixel.

4. The method of claim 1 , wherein identifying the set of nonstatic pixels includes identifying a set of nonstatic pixels that maintains the shallowest depth for a threshold consecutive number of depth maps in the series of depth maps.

5. The method of claim 1 , where identifying the set of nonstatic pixels includes defining a depth difference between a corresponding pixel in different depth maps from the series of depth maps;

for each pixel:

if the difference for that pixel is below a threshold, identifying that pixel as a static pixel; or

if the difference for that pixel is at or above the threshold, identifying that pixel as a nonstatic pixel.

6. The method of claim 1 , where the position of the set of nonstatic pixels is mapped to a cursor position according to a mapping function having a scale that changes as a function of a depth of the set of nonstatic pixels.

7. The method of claim 1 , where the position of the set of nonstatic pixels is mapped to a cursor position according to a mapping function, the mapping function having a scale that changes as a function of a size of the set of nonstatic pixels.

8. The method of claim 1 , where the position of the set of nonstatic pixels is mapped to a cursor position according to a mapping function, the mapping function having a scale that changes depending on which finger is identified as corresponding to the set of nonstatic pixels having the shallowest depth.

9. The method of claim 1 , where the surface imaged by the set of nonstatic pixels is a finger proximate a display device displaying a cursor at the cursor position, and where mapping the position of the set of nonstatic pixels to the cursor position includes shifting the cursor position away from a world space position of the finger.

10. The method of claim 1 , where the surface imaged by the set of nonstatic pixels is a finger that is not proximate a display device displaying a cursor at the cursor position.

11. The method of claim 10 , where the cursor operation includes one or more of a click operation, a double-click operation, a triple-click operation, a select operation, a highlight operation, a scroll operation, and a drag operation.

12. The method of claim 1 , further comprising tracking the set of nonstatic pixels throughout a consecutive number of depth maps in the series of depth maps and recognizing a cursor operation from one or more parameters of the set of nonstatic pixels in the consecutive number of depth maps.

13. The method of claim 12 , wherein the one or more parameters include a three-dimensional path of the set of nonstatic pixels.

14. The method of claim 1 , wherein receiving the series of depth maps includes receiving the series of depth from a time-of-flight depth camera.

15. The method of claim 1 , wherein receiving the series of depth maps includes receiving the series of depth from a structured light depth camera.

16. A computing device, comprising:

a depth camera input configured to receive a series of depth maps imaging a scene, each depth map including a plurality of pixels, each of the plurality of pixels defining a depth of a surface imaged by that pixel;

a logic subsystem configured to identify a set of nonstatic pixels having a shallowest depth within the series of depth maps and map a position of the set of nonstatic pixels to a cursor position; and

a display output configured to output a user interface including a cursor at the cursor position.