Human visual contrast detection of radial frequency stimuli defined by Bessel profiles j/sub 0/,j/sub 1/,j/sub 2/,j/sub 4/,j/sub 8/,j/sub 16/ and its relation to angular frequencies,

Abstract

We measured human contrast sensitivity to radial frequencies defined as Bessel profiles of n-order, i.e. j/sub 0/, j/sub 1/, j/sub 2/,j/sub 4/,j/sub 8/,j/sub 16/. Six curves of 11 experimental conditions (each) were measured three times by three observers (NAS, MLS, FMR) using a forced-choice method. The results show that contrast sensitivity is increased with the j/sub n/ order for n greater than zero, having distinct orderly effects at the low and high frequency ends. We interpret these results as being most consistent with the possibility that a spatial frequency processing by the human visual system can be defined a priori in terms of polar coordinates.