An apparatus for and method of performing a most informative feature
extraction (MIFE) method in which a facial image is separated into
sub-regions, and each sub-region makes individual contribution for
performing facial recognition. Specifically, each sub-region is subjected
to a sub-region based adaptive gamma (SadaGamma) correction or sub-region
based histogram equalization (SHE) in order to account for different
illuminations and expressions. A set of reference images is also divided
into sub-regions and subjected to the SadaGamma correction or SHE. A
comparison is made between the each corrected sub-region and each
corresponding sub-region of the reference images. Based upon the
comparisons made individually for the sub-regions of the facial image,
one of the stored reference images having the greatest correspondence is
chosen. While usable individually, using the MIFE and/or SadaGamma
correction or SHE together achieves a lower error ratio in face
recognition under different expressions, illuminations and occlusions.