spatial frequency

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frequency, spatial

The rate of alternation of the luminance in a visual stimulus as a function of length, usually expressed in cycles per degree. See cycle per degree; Fourier analysis; contrast sensitivity function.
References in periodicals archive ?
observed that contrast sensitivity at medium and high spatial frequencies decreases with increasing age, binocular values were higher than monocular values, and contrast sensitivity was higher in scotopic compared to photopic conditions (see pages 80-84).
Instead, what is significant is that we do not perceive all luminance contrasts, only those that are related to certain spatial frequencies.
The prediction was improved when the residuals were weighted to take account of the greater sensitivity to mid-range spatial frequencies, as in a published estimate of the contrast sensitivity function.
In fact, the P100 amplitude reduction of the amblyopic eyes in the esotropic group, as compared with the normal group, in both spatial frequencies and contrasts was recorded as statistically significant.
The aim of this study was to measure visual CS of achromatic luminance in alcohol abstainers by using vertical sinusoidal grating stimuli with spatial frequencies of 0.
increased intraocular light scatter, increased optical aberrations) that could affect the processing of high spatial frequencies (for a review see Ref.
Square wave grating targets in four random orientations (horizontal, vertical, right diagonal, and left diagonal) at six increasing spatial frequencies (0.
After analysing images of various poisonous animals, including the deathstalker scorpion and king cobra snake, they found similar patterns in terms of contrast and spatial frequencies to the trypophobic objects.
Contrast sensitivity (contrast sensitivity=1/contrast threshold) was measured in three spatial frequencies (SFs) of low [2 cycle per degree (cpd)], intermediate (5 cpd), and high (25 cpd)].
A reflection hologram recorded in a dry, acrylamide based photopolymer material, the hologram having a diffraction efficiency between about 25% and about 30% at spatial frequencies greater than 4500 lines mm.
y] are the highest spatial frequencies of the spatial frequency spectrum of the field c(x, y), which correspond to the field components with shortest periods.
RESULTS: Participants exposed to higher PCE levels exhibited lower contrast sensitivity at intermediate and high spatial frequencies compared with unexposed participants, although the differences were generally not statistically significant.

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