Patent Document ID: 8207963
Application ID: 11888377
Patent Status: 1

Claim One:
1. A computer-implemented system for performing motion capture of a subject comprising: a plurality of cameras for capturing a sequence of image frames of the subject over a period of time, each frame having a plurality of vertices defining a captured surface of the subject; a computing system for processing the sequence of image frames, the computing system having a memory for storing program code and a processor for processing the program code to perform the operations of: establishing a reference frame having one or more of the plurality of vertices and specifying a location for each of the vertices; performing frame-to-frame tracking to identify locations of vertices within an N′th frame based on locations of vertices within an (N−1)′th frame or an earlier frame; performing reference-to-frame tracking to identify locations of vertices within the N′th frame based on the locations of vertices in the reference frame to counter potential drift between the frames; storing the locations of vertices for use in subsequent reconstruction of the motion of the subject; and performing the frame-to-frame and reference-to-frame tracking again using a different set of parameters, the parameters defining a search area for the vertices of each frame wherein multiple correlation passes are performed with the different sets of parameters; and wherein for passes after the first, the search area is shrunk by using an estimate of the position of a vertex based on the position of nearby vertices that were successfully tracked in the previous passes.