A human face provides a variety of different communicative functions, such as identification, perception of emotional expressions, and lip-reading. Face perception is currently an active research area in the computer vision community.
Much research has been directed towards feature recognition in human faces. Three basic techniques are commonly used
for dealing with feature variations: correlation templates [1][2], deformable templates [3], and spatial image invariants
[4]. Several systems of locating human face have been reported. Eigenfaces, obtained by performing a principal
component analysis on a set of faces, are commonly used to identify faces [5]. By moving a window covering a subimage
over the entire image, faces can be located within the entire image. [6] reports a face detection system based on clustering techniques. The system passes a small window over all portions of the image, and determines whether a face exists in each window. A similar system with better results has been claimed by [7]. A different approach for locating and tracking faces is described in [8]. This system locates faces by searching for the skin-color. After locating a face, the system extracts additional features to match this particular face. Recently, Pfinder [9] uses skin-color to track human body.