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;
obtaining a calculated distance between the first and second objects calculated for the selection using spatial coordinates obtained 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 obtaining spatial coordinates for the first and second objects from additional captured images of 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 reached by the calculated distance; and
responsive to the threshold value being reached, performing the adjusting on the at least one camera parameter after the threshold value is reached.
3. The method of claim 1 , further including:
filtering 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:
obtaining 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:
obtaining a distance between the objects and at least one camera of the one or more cameras; and
responsive to the 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 identified in images captured by one or more cameras by a gesture;
obtaining a calculated distance between the first and second objects using spatial coordinates obtained 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 obtaining additional spatial coordinates for the first and second objects.
16. The non-transitory computer readable storage medium of claim 15 , implementing the method further including obtaining an altered view of a virtual scene from a point of view of a virtual camera, the altered view of the virtual scene moved in responsive to the calculated distance.
17. The non-transitory computer readable storage medium of claim 15 , implementing the method further including obtaining an altered view of a virtual scene from a point of view of a virtual camera, the altered view of the virtual scene narrowed responsive to reduction in the calculated distance or widened responsive to increase in the calculated distance.
18. The non-transitory computer readable storage medium of claim 15 , implementing the method further including obtaining an altered view of a virtual scene from a point of view of a virtual camera, wherein size or shape of virtual elements in the altered view of the virtual scene has been adjusted responsive to the calculated distance.
19. The non-transitory computer readable storage medium of claim 15 , implementing the method further including obtaining an altered view of a virtual scene from a point of view of a virtual camera, wherein responsiveness of virtual elements in the altered view of the virtual scene has been adjusted 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 at least one of the first and second objects; wherein the gestures made by the at least one of the first and second objects control the virtual elements more precisely with reduction in the calculated distance; and
responsive to increase in the calculated distance, altering responsiveness of one or more virtual elements to gestures made by at last one of the first and second objects; wherein the gestures made by the at least one of the first and second objects control the virtual elements more coarsely with increasing calculated distance.