Introduction - If you have any usage issues, please Google them yourself
		 
The way this algorhitm works is by treating face recognition as a
 * two-dimensional recognition problem, taking advantage of the fact that
 * faces are normally upright and thus may be described by a small set
 * of 2-D characterisits views. Face images are projected onto a
 * feature space ( face space ) that best encodes the variation
 * among known face images. The face space is defined by the
 * eigenfaces , which are the eigenvectors of the set of faces 
 * they do not necessarily correspond to isolated features such as eyes,
 * ears, and noses. (quoted the paper s abstract)