Tracking an object with multiple asynchronous cameras
First Claim
1. A method for determining a position of a moving object, comprising:
- receiving first, second and third images of the moving object, a first camera captures the first and third images, a second camera captures the second image asynchronously to the first camera capturing the first and third images, the first, second and third images are captured at first, second and third time points, respectively;
determining a location of the moving object in the first image in a pixel space of the first camera, and a first vector which extends from an origin of a coordinate system of the first camera to the location of the moving object in the pixel space of the first camera;
determining a location of the moving object in the second image in a pixel space of the second camera, and a second vector which extends from an origin of a coordinate system of the second camera to the location of the moving object in the pixel space of the second camera, the coordinate system of the second camera is different than the coordinate system of the first camera;
determining a location of the moving object in the third image in the pixel space of the first camera, and a third vector which extends from the origin of the coordinate system of the first camera to the location of the moving object in the pixel space of the first camera;
transforming, to a world coordinate system, the first and third vectors from the coordinate system of the first camera, and the second vector from coordinate system of the second camera;
determining an instantaneous position of the moving object in the world coordinate system at a time point which is different than the first, second and third time points, by determining a position in 3-d space which satisfies a metric, the metric is based on a first distance from the position in 3-d space to a first line represented by the first vector, a second distance from the position in 3-d space to a second line represented by the second vector, and a third distance from the position in 3-d space to a third line represented by the third vector; and
enhancing a video signal to depict the instantaneous position of the moving object.
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Accused Products
Abstract
The path and/or position of an object is tracked using two or more cameras which run asynchronously so there is need to provide a common timing signal to each camera. Captured images are analyzed to detect a position of the object in the image. Equations of motion for the object are then solved based on the detected positions and a transformation which relates the detected positions to a desired coordinate system in which the path is to be described. The position of an object can also be determined from a position which meets a distance metric relative to lines of position from three or more images. The images can be enhanced to depict the path and/or position of the object as a graphical element. Further, statistics such as maximum object speed and distance traveled can be obtained. Applications include tracking the position of a game object at a sports event.
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Citations
20 Claims
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1. A method for determining a position of a moving object, comprising:
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receiving first, second and third images of the moving object, a first camera captures the first and third images, a second camera captures the second image asynchronously to the first camera capturing the first and third images, the first, second and third images are captured at first, second and third time points, respectively; determining a location of the moving object in the first image in a pixel space of the first camera, and a first vector which extends from an origin of a coordinate system of the first camera to the location of the moving object in the pixel space of the first camera; determining a location of the moving object in the second image in a pixel space of the second camera, and a second vector which extends from an origin of a coordinate system of the second camera to the location of the moving object in the pixel space of the second camera, the coordinate system of the second camera is different than the coordinate system of the first camera; determining a location of the moving object in the third image in the pixel space of the first camera, and a third vector which extends from the origin of the coordinate system of the first camera to the location of the moving object in the pixel space of the first camera; transforming, to a world coordinate system, the first and third vectors from the coordinate system of the first camera, and the second vector from coordinate system of the second camera; determining an instantaneous position of the moving object in the world coordinate system at a time point which is different than the first, second and third time points, by determining a position in 3-d space which satisfies a metric, the metric is based on a first distance from the position in 3-d space to a first line represented by the first vector, a second distance from the position in 3-d space to a second line represented by the second vector, and a third distance from the position in 3-d space to a third line represented by the third vector; and enhancing a video signal to depict the instantaneous position of the moving object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system for determining a position of a moving object used at an event, comprising:
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a plurality of cameras capturing first, second and third images of the moving object, the first, second and third images are captured at first, second and third successive time points, the plurality of cameras comprise a first camera which captures the first and third images and a second camera which captures the second image asynchronously to the first camera capturing the first and third images; and a processor which receives the first, second and third images from the plurality of cameras, the processor;
determines a location of the moving object in the first image in a pixel space of the first camera, and a first vector which extends from an origin of a coordinate system of the first camera to the location of the moving object in the pixel space of the first camera, determines a location of the moving object in the second image in a pixel space of the second camera, and a second vector which extends from an origin of a coordinate system of the second camera to the location of the moving object in the pixel space of the second camera, determines a location of the moving object in the third image in the pixel space of the first camera, and a third vector which extends from an origin of the coordinate system of the first camera to the location of the moving object in the pixel space of the first camera, transforms, to a world coordinate system, the first and third vectors from the coordinate system of the first camera, and the second vector from coordinate system of the second camera, and, to determine an instantaneous position of the moving object in the world coordinate system at a time point which is different than the first, second and third time points, determines a position in 3-d space which satisfies a metric, the metric is based on a first distance from the position in 3-d space to a first line represented by the first vector, a second distance from the position in 3-d space to a second line represented by the second vector, and a third distance from the position in 3-d space to a third line represented by the third vector. - View Dependent Claims (11, 12, 13)
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14. A processor readable storage device comprising processor readable code embodied thereon for programming a processor to perform a method, the method comprising:
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determining a location of a moving object in a first image in a pixel space of a first camera, and a first vector which extends from an origin of a coordinate system of the first camera to the location of the moving object in the pixel space of the first camera; determining a location of the moving object in a second image in a pixel space of a second camera, and a second vector which extends from an origin of a coordinate system of the second camera to the location of the moving object in the pixel space of the second camera; determining a location of the moving object in a third image in the pixel space of the first camera, and a third vector which extends from an origin of the coordinate system of the first camera to the location of the moving object in the pixel space of the first camera; transforming, to a world coordinate system, the first and third vectors from the coordinate system of the first camera, and the second vector from coordinate system of the second camera; and determining an instantaneous position of the moving object in the world coordinate system, by determining a position in 3-d space which satisfies a metric, the metric is based on a first distance from the position in 3-d space to a first line represented by the first vector, a second distance from the position in 3-d space to a second line represented by the second vector, and a third distance from the position in 3-d space to a third line represented by the third vector. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification