In order to save time to magnify or shrink an eigenimage to meet the size of the test image, a group of
eigenimages was stored in the database so that an appropriate eigenimage can be called with ease
without going through image enlarging or shrinking process. The eigenimages were stored in 20 files
from 30 pixel-width square image to 220 pixel-width square image with 10-pixel step. The stored
eigenimages were normalized by means of dividing the image matrix by its 2nd
norm so that the effect
of eigenimage size does not affect the face detection algorithm.