System and method for object tracking
A hand-manipulated prop is picked-up via a single video camera, and the camera image is analyzed to isolate the part of the image pertaining to the object for mapping the position and orientation of the object into a three-dimensional space, wherein the three-dimensional description of the object is stored in memory and used for controlling action in a game program, such as rendering of a corresponding virtual object in a scene of a video display. Algorithms for deriving the three-dimensional descriptions for various props employ geometry processing, including area statistics, edge detection and/or color transition localization, to find the position and orientation of the prop from two-dimensional pixel data. Criteria are proposed for the selection of colors of stripes on the props which maximize separation in the two-dimensional chrominance color space, so that instead of detecting absolute colors, significant color transitions are detected. Thus, the need for calibration of the system dependent on lighting conditions which tend to affect apparent colors can be avoided.
1 . An object tracking system comprising:
an input device configured to detect two-dimensional input pixel data from a prop device; and
a multiprocessor unit configured to calculate three-dimensional position and orientation data associated with the prop device from the two-dimensional input pixel data.
2 . The object tracking system of claim 1 wherein the multiprocessor unit further comprises a memory configured to store the three-dimensional position and orientation data associated with the prop device.
3 . The object tracking system of claim 1 wherein the multiprocessor unit further comprises an image processor configured to execute operations for rendering the three-dimensional position and output data associated with the prop device.
4 . The object tracking system of claim 1 further comprising a monitor for displaying action in a game program caused by rendering the three-dimensional position and output data associated with the prop device.
5 . The object tracking system of claim 1 further comprising the prop device configured to provide input data.
6 . The object tracking system of claim 1 wherein the input device is a camera.
7 . The object tracking system of claim 2 wherein the memory further comprises a display rendering region.
8 . The object tracking system of claim 2 wherein the memory further comprises a texture rendering region.
9 . A machine readable medium having embodied thereon a program being executable by a machine to perform a method for tracking and discriminating pixel groups, the method comprising:
receiving pixel data from an input device;
segmenting color whereby the color of each pixel is determined and the image is divided into two-dimensional segments of colors;
defining edges of an object in the image; and
calculating three-dimensional position and orientation data of the object.
10 . The machine readable medium of claim 9 wherein the method further comprises localizing color transitions whereby distinct color transitions are defined.
11 . The machine readable medium of claim 9 wherein the method further comprises filtering the three-dimensional position and orientation data.
12 . The machine readable medium of claim 9 wherein defining edges of an object employs an edge detection process.
13 . The machine readable medium of claim 9 wherein defining edges of an object employs performing calculations for area statistics.
14 . The machine readable medium of claim 9 wherein a definition of an edge of the object is algebraic.
15 . The machine readable medium of claim 9 wherein the definition of an edge of the object is geometric.
16 . The machine readable medium of claim 11 wherein the filtering comprises Kalman filtering.
17 . A method for tracking and discriminating pixel groups comprising:
receiving pixel data from an input device;
segmenting color whereby the color of each pixel is determined and the image is divided into two-dimensional segments of colors;
defining edges of an object in the image; and
calculating three-dimensional position and orientation data of the object.
18 . The method of claim 17 further comprising localizing color transitions whereby distinct color transitions are defined prior to defining the edges of the object in the image.
19 . The method of claim 17 further comprising filtering the three-dimensional position and orientation data.
20 . A system for tracking and discriminating pixel groups comprising:
means for receiving pixel data from an input device;
means for segmenting color whereby the color of each pixel is determined and the image is divided into two-dimensional segments of colors;
means for defining edges of an object in the image; and
means for calculating three-dimensional position and orientation data of the object.