Adjusting motion capture based on the distance between tracked objects
View Patent ↗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 motion capture using a distance of two or more objects in a 3D monitored space, the method including:
identifying from images captured by one or more cameras, first and second objects present in a 3D monitored space, wherein the first and second objects are first and second objects are identified as objects to be tracked responsive to selection of the first and second objects by a touch gesture;
calculating spatial coordinates for the first and second objects present in the 3D monitored space based upon the images captured by the one or more cameras and calculating a calculated distance between the first and second objects in space from the spatial coordinates; and
responsive to the calculated distance, adjusting at least one parameter of motion capture; whereby adjusting the at least one parameter of motion capture enables capturing additional images of the first and second objects and repeatedly calculating spatial coordinates for 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 parameter of motion capture 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 touch 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 from a user for 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 parameter of motion capture 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 parameter of motion capture.
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:
identifying first and second objects physically present in fields of view of one or more cameras from images of the 3D monitored space captured by the one or more cameras, wherein the first and second objects are identified as objects to be tracked responsive to selection of the first and second objects by a touch gesture;
calculating spatial coordinates for the first and second objects physically present in the 3D monitored space based upon the images captured by the one or more cameras and calculating a calculated distance between the first and second objects from the spatial coordinates; and
responsive to the calculated distance between the first and second objects physically present in fields of view of the one or more cameras, altering a view of a virtual scene from a point of view of the virtual camera and 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 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 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 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 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.