title: Effect of spatial frequency on the visibility of unstructured patterns.
abstract: Threshold measurements have been made on random patterns that  have been computer filtered to contain only certain spatial frequencies. The dependence of threshold on the spatial-frequency distribution of the energy in the patterns was measured. The results indicate that the visibility of an unstructured pattern is dependent on the spatial-frequency content of the pattern. Near threshold, narrow-band noise is much more visible than wide-band noise. The narrow-band noise visibility is caused by the presence of structure in the pattern, some of which is rotation sensitive. For wider-band noise, the modulation transfer function is circularly symmetric. The visibility of very-wide-band noise near threshold depends only on the luminance variations concentrated within a one-octave spatial-frequency band.
mesh_terms: D006801:Humans; D010507:Periodicity; D010775:Photic Stimulation; D011601:Psychophysics; D014796:Visual Perception