Abstract

This paper presents a systmatic analysis of Gabor filter banks for detection of facial landmarks (eyes and philtrum) on the FERET database. Sensitivity is assessed using the A' statistic, a nonparametric estimate of optimal performance commonly used in the psychophysical literature. We find that current Gabor filter bank systems are overly complex. Performance can be greatly improved by reducing the number of frequency and orientation components in these systems. With a single frequency band, we obtained performances significantly better than those achievable with current systems that use multiple frequency bands. Best performance for eye location was obtained with filter banks peaking at 4 iris widths per cycle and 8 orientations. Best performance for philtrum location was achieved with filter banks with 5.5 iris widths per cycle and 8 orientations.