The effect of bandpass filtering on the efficiency of complex pattern identification

Purpose. To measure the efficiency with which observers use spatial frequency information when identifying complex visual patterns. Methods. Stimuli were 1 and 2 octave wide bandpass filtered English letters and familiar faces embedded in 2D dynamic Gaussian noise. Center frequencies of the filtered images ranged from 1.4 cycles/image to 90.5 cycles/image. Human and cross-correlator contrast variance thresholds for 67% correct identification …