A methodology is described to reduce the complexity of filters for face
recognition by reducing the memory requirement to, for example, 2
bits/pixel in the frequency domain. Reduced-complexity correlations are
achieved by having quantized MACE, UMACE, OTSDF, UOTSDF, MACH, and other
filters, in conjunction with a quantized Fourier transform of the input
image. This reduces complexity in comparison to the advanced correlation
filters using full-phase correlation. However, the verification
performance of the reduced complexity filters is comparable to that of
full-complexity filters. A special case of using 4-phases to represent
both the filter and training/test images in the Fourier domain leads to
further reductions in the computational formulations. This also enables
the storage and synthesis of filters in limited-memory and
limited-computational power platforms such as PDAs, cell phones, etc. An
online training algorithm implemented on a face verification system is
described for synthesizing correlation filters to handle pose/scale
variations. A way to perform efficient face localization is also
discussed. Because of the rules governing abstracts, this abstract should
not be used to construe the claims.