Patent ID: 7343278

Claim:
A method in a computing system for tracking movement of a surface having an arbitrary appearance relative to a camera, comprising: capturing an image of the surface using the camera; analyzing the captured image of the surface to identify visual features present in the captured image; from the identified visual features, selecting a plurality of visual features for use in tracking the movement of the surface, wherein the selection of visual features is performed based upon a comparison of levels of contrast provided by each of the identified features; receiving a sequence of images captured by the camera, at least some of which constitute a view of at least a portion of the surface; for each image of the sequence: identifying 2-dimensional positions at which the selected features occur in the image; and based upon the 2-dimensional positions at which the selected features are identified in the image, determining 3-dimensional location and orientation of the surface in the image of the sequence with respect to the camera; using the determined location and orientation of the surface to introduce a supplemental image into the images of the sequence at a size, location, and orientation that are relative to those of the surface to obtain an augmented sequence of images; and displaying the augmented sequence of images using a computer display.