Adjusting motion capture based on the distance between tracked objects
The technology disclosed relates to adjusting the monitored field of view of a camera and/or a view of a virtual scene from a point of view of a virtual camera based on the distance between tracked objects. For example, if the user's hand is being tracked for gestures, the closer the hand gets to another object, the tighter the frame can become—i.e., the more the camera can zoom in so that the hand and the other object occupy most of the frame. The camera can also be reoriented so that the hand and the other object remain in the center of the field of view. The distance between two objects in a camera's field of view can be determined and a parameter of a motion-capture system adjusted based thereon. In particular, the pan and/or zoom levels of the camera may be adjusted in accordance with the distance.
1. A method of adjusting a camera parameter using a distance of two or more objects in a 3D monitored space, the method including:
receiving a selection of first and second objects in a 3D monitored space identified in images captured by one or more cameras using a gesture;
calculating a calculated distance between the first and second objects in the selection using spatial coordinates determined for the first and second objects; and
responsive to the calculated distance, adjusting at least one camera parameter; whereby adjusting the at least one camera parameter enables repeatedly calculating spatial coordinates for the first and second objects from additional images capturing the first and second objects.
2. The method of claim 1 , further including:
establishing a threshold value to be set for the calculated distance;
detecting the threshold value is crossed by the calculated distance; and
responsive to detecting the threshold value is crossed, performing the adjusting on the at least one camera parameter continuously, after the threshold value is reached.
3. The method of claim 1 , further including:
using a filter to eliminate spurious changes in the calculated distance detected in the images.
4. The method of claim 1 , wherein the adjusting includes:
adjusting a frame rate of at least one of the one or more cameras, based at least in part upon the calculated distance.
5. The method of claim 1 , wherein the adjusting includes:
adjusting lighting conditions based at least in part upon the calculated distance.
6. The method of claim 1 , wherein the adjusting includes:
moving a field of view of at least one of the one or more cameras responsive to the calculated distance.
7. The method of claim 1 , further including identifying the gesture using the one or more cameras.
8. The method of claim 1 , further including identifying first and second objects as objects to be tracked responsive to changing distance between first and second objects.
9. The method of claim 1 , wherein the first object is a first finger of a hand of a user and the second object is another finger of the hand of the user.
10. The method of claim 1 , wherein the first object is a hand of a user and the second object is another hand of the user.
11. The method of claim 1 , wherein the first object is a hand of a user and the second object is a fixed object or a moving object.
12. The method of claim 1 , further including receiving a specification of reference points on the objects dependent on which distance between the objects is calculated.
13. The method of claim 1 , further including:
determining a rate of change for the calculated distance; and
altering the at least one camera parameter responsive to the rate of change of the calculated distance.
14. The method of claim 1 , further including:
calculating distance between the objects and at least one camera of the one or more cameras; and
responsive to the calculated distance between the objects and the at least one camera, altering the at least one camera parameter.
15. A non-transitory computer readable storage medium impressed with computer program instructions to control a virtual camera responsive to distance between two or more objects in a 3D monitored space, which computer program instructions, when executed on a processor, implement a method including:
receiving a selection of first and second objects in a 3D monitored space identified in images captured by one or more cameras using a gesture;
calculating a calculated distance between the first and second objects using spatial coordinates determined for the first and second objects; and
responsive to the calculated distance between the first and second objects, adjusting at least one camera parameter; whereby adjusting the at least one camera parameter enables repeatedly calculating spatial coordinates for the first and second objects.
16. The non-transitory computer readable storage medium of claim 15 , implementing the method further including altering a view of a virtual scene from a point of view of a virtual camera and moving the view of the virtual scene responsive to the calculated distance.
17. The non-transitory computer readable storage medium of claim 15 , implementing the method further including altering a view of a virtual scene from a point of view of a virtual camera and narrowing the view of the virtual scene responsive to reduction in the calculated distance or widening the view of the virtual scene responsive to increase in the calculated distance.
18. The non-transitory computer readable storage medium of claim 15 , implementing the method further including altering a view of a virtual scene from a point of view of a virtual camera and adjusting size or shape of virtual elements in the virtual scene responsive to the calculated distance.
19. The non-transitory computer readable storage medium of claim 15 , implementing the method further including altering a view of a virtual scene from a point of view of a virtual camera and adjusting responsiveness of virtual elements in the virtual scene responsive to the calculated distance.
20. The non-transitory computer readable storage medium of claim 15 , implementing the method further including at least one of:
responsive to reduction in the calculated distance, altering responsiveness of one or more virtual elements to gestures by the first or second object; wherein the gestures by the first or second object more precisely control the virtual elements and
responsive to increase in the calculated distance, altering responsiveness of one or more virtual elements to gestures by the first or second object; wherein the gestures by the first or second object more coarsely control the virtual elements.
21. The non-transitory computer readable storage medium of claim 20 , implementing the method further including increasing responsiveness of the virtual elements responsive to increase in the calculated distance or decreasing responsiveness of the virtual elements responsive to reduction in the calculated distance.