Paul van Diepen - Spatial Frequency Filtering of Scenes

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Stimuli subtended 16 x 12 visual degrees, whereas the window size was 6 x 4.6 degrees. The window was always centered on the fixation position. In the examples below the subject is fixating the small boat. The low-pass filter removed all spatial frequencies above 1 cycl./degr. The high-pass filter removed all frequencies below 3 cycl./degr., but maintained the static Fourier component (i.e. the average grey level). Within the window the normal, full-frequency stimulus appeared. 

Control Stimulus (the white ellipse is centered on the fixation position):

control stimulus

Low-pass filtered stimulus in periphery

low-pass filtered stimulus

High-pass filtered stimulus in periphery

high-pass filtered

Paul M. J. van Diepen - October 2002