TRUE SPACE TRACKING OF AXISYMMETRIC OBJECT FLIGHT USING DIAMETER MEASUREMENT

摘要

Methods and apparatus for determining a trajectory of a axisymmetric object in 3-D physical space using a digital camera which records 2-D image data are described. In particular, based upon i) a characteristic length of the axisymmetric object, ii) a physical position of the camera determined from sensors associated with the camera (e.g., accelerometers) and iii) captured 2-D digital images from the camera including a time at which each image is generated relative to one another, a position, a velocity vector and an acceleration vector can be determined in three dimensional physical space for axisymmetric object objects as a function of time. In one embodiment, the method and apparatus can be applied to determine the trajectories of objects in games which utilize axisymmetric object objects, such as basketball, baseball, bowling, golf, soccer, rugby or football.

主权项

1. An electronic device comprising:
a housing; a wireless network interface; a camera lens coupled to an exterior of the housing; an input interface; and a processor communicatively coupled to the input interface and a digital image sensor disposed within an interior of the housing wherein the digital image sensor receives light which passes through the camera lens; the processor configured to 1) receive a plurality of 2-D digital images from the digital image sensor, 2) output the plurality of 2-D digital images to the display, 3) select a portion of the plurality of 2-D digital images wherein the portion is selected based upon at least whether an axisymmetric object in free flight used in a play of a game is identifiable, 4) receive input data from the input mechanism which is used to determine an orientation of the camera lens in a first reference frame; 5) based upon the orientation of the camera lens in the first reference frame, transform first pixel data in each of the portion of the plurality of 2-D digital images from the first reference frame associated with a current orientation of the camera lens to second pixel data associated with a second reference frame; 6) determine a plurality of first pixel lengths across the axisymmetric object in multiple directions of the second pixel data in each of the portion of the plurality of 2-D digital images to account for motion blurring and light blooming effects; 7) based upon the plurality of first pixel lengths, determine a first characteristic pixel length of the axisymmetric object in each of the portion of the plurality of 2-D digital images; 8) based upon first characteristic pixel length, determine distances from the camera lens to the axisymmetric object in physical space in each of the portion of the plurality of 2-D digital images; 9) determine a center of the axisymmetric object in the second pixel data in each of the 2-D digital images; 10) determine a plurality of second pixel lengths which measure changes in the center of the axisymmetric object between each of the portion of the plurality of 2-D digital images; 11) based upon the plurality of second pixel lengths and the distances from the camera lens, determine a 3-D trajectory of the axisymmetric object as a function of time in physical space, 12) select one of the plurality of 2-D digital images, 13) render a path showing the 3-D trajectory of the axisymmetric object into the selected one of the plurality of 2-D digital images and 14) output to the display a new 2-D digital image including the path of the 3-D trajectory.