| 摘要 |
A process of video capture, segmentation, tracking, and mapping to obtain position and time data for motion analysis. The moving object is captured in video in a series of frames at a known frame rate. The moving object is isolated from all other data in a frame and the position of the moving object is determined relative to stationary reference elements in the frame. However, the video captures a physical, three-dimensional space, in a two-dimensional image, causing distortions. This method associates all points in the quadrilateral with a rectangle defined by sides in real, physical space using a vanishing point algorithm. The preferred vanishing point algorithm maps a physical space to a quadrilateral defined by two sides that intersect at a first vanishing point, and two other sides that intersect at a second vanishing point. Single-point or three-point perspective may also be employed. Once associated, the position in the quadrilateral can be translated to Cartesian coordinates in the rectangle, thereby permitting the accurate determination of an object's position in physical space from a two-dimensional image. The algorithm correlates the midpoint on a side of the quadrilateral from the frame to the midpoint on a side of the rectangle in physical space.
|
