Modeling and subsequent analysis of the user utilizes the Gaussian blobs described above, incorporating both spatial and color information.
Figure 3.2:
To initialize the blob models, Pfinder uses
features found by a contour analysis module.
To initialize blob models, a 2D contour shape analysis that attempts to identify the head, hands, and feet locations (see Fig. 3.2). When this contour analysis does identify one of these locations, then a new blob is created and placed at that location. For hand and face locations, the blobs have strong flesh-colored color priors. Other blobs are initialized to cover clothing regions.
The blobs introduced by the contour analysis compete with all the other blobs to describe the data. As a consequence, there are typically only seven blobs required: three for head and hands, two for feet, and one each for shirt and pants.