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Neitz M - - 2000
Color is an extremely important component of the information that we gather with our eyes. Most of us use color so automatically that we fail to appreciate how important it is in our daily activities. It serves as a nonlinguistic code that gives us instant information about the world around ...
Eckert M P - - 2000
Large color variations can be observed across the face of a flower even when individual petals are the same color. We investigated whether these color variations could be explained by a model that incorporates multiple reflections of light between petals and transmissions of light through petals before the light returns ...
Henry R C - - 2000
The radiance of most objects seen at a distance through the atmosphere is dominated by scattered light of a blue hue that should make the landscape appear predominately blue. However, common experience shows that people can see colors at a distance. A possible explanation of this paradox is that the ...
Kim T H - - 2000
The image quality of a color liquid-crystal display monitor is studied by changing the contrast and the luminance levels. The resolution is assessed with modulation transfer function area (MTFA) that is measured at nine different combinations of the luminance and contrast. At these combinations, we measure the chromaticity coordinates and ...
Sokolov E N - - 2000
Despite a wide variety of emotions that can be subjectively experienced, the emotion space has consistently revealed a low dimensionality. The search for corresponding somato-visceral response patterns has been only moderately successful. The authors suggest a solution based on an assumed parallelism between emotion coding and color coding. According to ...
Reisfeld P L - - 2000
BACKGROUND: The most prevalent theory explaining blue colors in skin is that of bluish scatter. If this accounted for blue perception, it would be measurable since a predominance of scattered blue light should emerge as a measurable reflectance. When objects are viewed with chromatic surround, there may be an increased ...
Sokolov E N - - 2000
Color perception is dependent on the generation of an excitation vector which, acting on a pool of color detectors (color detector map), produces a corresponding sensation. The generation of the color excitation vector starts at the retinal level, proceeds in the lateral geniculate body, and reaches color detectors at the ...
Purves D - - 2000
Four different colors are needed to make maps that avoid adjacent countries of the same color. Because the retinal image is two dimensional, like a map, four dimensions of chromatic experience would also be needed to optimally distinguish regions returning spectrally different light to the eye. We therefore suggest that ...
Bouquet C - - 2000
Hypoxia is known to alter visual functions. In the present study, the effects of chronic hypobaric hypoxia upon visual color discrimination were studied in 8 subjects participating in a simulated climb from sea level (PO2 = 210 hPa) to 8,848 m (PO2 = 70 hPa) over a 31-day period of ...
Wolffsohn J S - - 2000
PURPOSE: Although many studies have shown a subjective preference for yellow lenses, there has been little success in determining the clinical nature of this benefit. METHOD: Contrast sensitivity, color vision, accommodative-convergence, and visual acuity were measured in a group of 20 young subjects along with subjective rating of their perception ...
Chiao C C - - 2000
Multispectral images of natural scenes were collected from both forests and coral reefs to represent typical, complex scenes that might be viewed by modern animals. Both reflectance spectra and modeled visual color signals in these scenes were decorrelated spectrally by principal-component analysis. Nearly 98% of the variance of reflectance spectra ...
Schirillo J A - - 2000
Color matches between two small patches were made in a display containing ten larger regions of different chromaticities. The spatial organization of the ten regions was varied while keeping constant the immediate surround of each patch as well as the space-average chromaticity of the entire stimulus. Different spatial arrangements were ...
Rinner O - - 2000
Adaptation to a steady background has a profound effect on both color appearance and discrimination. We determined the temporal characteristics of chromatic adaptation for appearance and discrimination along different color directions. Subjects were adapted to a large uniform background made up of a CRT screen and a 45x64 degrees wall, ...
Beer R D - - 2000
The gamut of perceived colors can be represented in a space with bright-dark, red-green and blue-yellow axes. Pre-exposure to a field that changes periodically over time in luminance or along one of the color axes reduces vividness of colors along the entire axis [Webster and Mollon (1991) Nature, 349, 235-238]. ...
Rich A - - 2000
A new technique for measuring change detection was introduced in which contours rotating in depth around a vertical axis (in a computer display) could be altered in color as they passed through their point of minimum extension (the median plane) where a thin static vertical occluder hid the change. Sets ...
Tailor D R - - 2000
Independent Component Analysis (ICA) of images of natural scenes has been shown to generate basis functions, or filters, which resemble spatial [Bell & Sejnowski (1997). Vision Research, 37, 3327-3338; van Hateren & van der Schaaf (1998). Proceedings of the Royal Society of London B, 265, 359-366] and spatiotemporal [van Hateren ...
Webster M A - - 2000
Color appearance depends on adaptation processes that adjust sensitivity both to the average color in the stimulus (through light or chromatic adaptation) and to the variations in color (through contrast adaptation). We explored how these different forms of adaptation interact, by examining how the state of chromatic adaptation depends on ...
Kurtz D B - - 2000
Fundamental to the concept of psychological distance is the idea that confusability allows discovery of the perceptual relationships between objects, which provides understanding of the underlying principles that govern the functioning of a system. Thus, judgments of dissimilarity (conceptually proportional to the inverse of confusability) may provide insight into the ...
Fidopiastis C - - 2000
Color-from-motion displays consist of a sparse array of dots which never move but change color according to various algorithms. Yet such displays can trigger human vision to construct apparent motion of a subjective surface which is uniformly colored and bounded by a subjective contour. We show that the perceptual strength ...
Shevell S K - - 2000
The color appearance of a light can be altered by introducing a second, surrounding field. This phenomenon, called chromatic induction, is attenuated by chromatic variation within a remote region outside the surround [Shevell & Wei (1998). Vision Research, 38, 1561-1566]. We now consider the locus of the neural mechanism mediating ...
Loop M S - - 2000
Psychophysical (behavioral) detection thresholds and color-discrimination thresholds were determined in a macaque using a two-alternative forced-choice procedure. On a white background, detection thresholds were determined for a white increment and three spectral increments: 618, 516, and 456 nm. Intermixed with detection threshold determinations, color-discrimination thresholds were determined by presenting the ...
Nothdurft H - - 2000
Test targets ('singletons') that displayed orientation, motion, luminance, or color contrast, or pairwise combinations of these, were presented in line texture arrays, and their saliences were quantified in comparison to reference targets at defined luminance levels. In general, saliency effects in different stimulus dimensions did add, but did not add ...
Zhai H - - 1999
We first discuss the restriction on the incoherent source and the color filters in a joint transform correlation (JTC) system for white-light color pattern recognition and then report on a novel, to our knowledge, solution of channeling in a white-light JTC system, using a tricolor grating to encode the color ...
Dougherty R F - - 1999
The influence of contrast and color on perceived motion was measured using a speed-matching task. Observers adjusted the speed of an L cone contrast pattern to match that of a variety of colored test patterns. The dependence of speed on test contrast was the same for all test colors measured, ...
Hübner R - - 1999
In 4 experiments, stimulus elements were arranged into an LED-like array, and letters were defined within the array by feature similarity between the elements with respect to color and form. These stimuli allowed the display of a target and a distractor letter simultaneously at the same location. They were spatially ...
O'Connor KI - - 1999
Communication by means of visual signals occurs during the competitive, aggressive and sexual interactions of many animals. Some animals such as fish are able to change their body coloration rapidly, and there is evidence that this is used as a means of signalling. However, the precise meaning of such signals ...
Palmer S E - - 1999
The relations among consciousness, brain behavior, and scientific explanation are explored in the domain of color perception. Current scientific knowledge about color similarity, color composition, dimensional structure, unique colors, and color categories is used to assess Locke's "inverted spectrum argument" about the undetectability of color transformations. A symmetry analysis of ...
Lotto R B - - 1999
Observation of human subjects shows that the spectral returns of equiluminant colored surrounds govern the apparent brightness of achromatic test targets. The influence of color on brightness provides further evidence that perceptions of luminance are generated according to the empirical frequency of the possible sources of visual stimuli, and suggests ...
Bimler D - - 1999
Individual-differences multidimensional scaling was applied to a set of proximity data for equiluminant lights (Paramei & Cavonius, 1999) to explore any differences between two data collection procedures (rated dissimilarities, and same/different response times [RTs]), as well as between color-normal and abnormal observers. Two conclusions emerged: (1) The pattern of similarities ...
Pridmore R W RW Central Houses Proprietary Limited, Sydney, NSW, - - 1999
For spectral and nonspectral aperture color 3 s stimuli, Bezold-Brucke (B-B) hue-shift was measured for one to six subjects for four functions: (1) luminance (L) level from 0.1:1.0 through 100:1000 cd/m2; (2) L ratio from 1:2 through 1:1000; (3) illuminant color temperature (for seven illuminants including A and D65) by ...
Pridmore R W - - 1999
For aperture color 3 s stimuli, the four unique hues, and at times the four (equally-balanced) binary hues, were measured for: (1) adapting white color temperatures 2850, 3400, 5500, 6500 K; and (2) luminance (L) for 5 and 6 log L ranges (about 0.01-3200 cd/m2) in 3.2:1 L steps (viewed ...
Sankeralli M J - - 1999
We use psychophysical techniques to investigate the neural mechanisms subserving suprathreshold chromatic discrimination in human vision. We address two questions: (1) How are the postreceptoral detection mechanism responses combined to form suprathreshold chromatic discriminators? and (2) How do these discriminators contribute to color perception? We use a pedestal paradigm in ...
Paramei G V - - 1999
With multidimensional scaling analysis, color spaces were reconstructed from reaction times (RTs) required to make same-different judgements of pairs of 15 equiluminant colors and from dissimilarity ratings between them. In addition to normal trichromats, observers with red-green color deficiency were tested. Two main purposes were served by this study: (1) ...
Roe A W - - 1999
To examine the functional interactions between the color and form pathways in the primate visual cortex, we have examined the functional connectivity between pairs of color oriented and nonoriented V1 and V2 neurons in Macaque monkeys. Optical imaging maps for color selectivity, orientation preference, and ocular dominance were used to ...
Lee D K - - 1999
We report a series of experiments on the concurrent discrimination of form, color, and motion attributes. All tasks involved joint discrimination of attributes, and positions and were highly demanding of attention. We quantified interference between concurrent discriminations by establishing the attention-operating characteristic. Interference was indistinguishable for similar and dissimilar task ...
Neitz J - - 1999
Protanomaly is a common, X-linked abnormality of color vision. Like people with normal color vision, protanomalous observers are trichromatic, but their ability to discriminate colors in the red-green part of the spectrum is reduced because the photopigments that mediate discrimination in this range are abnormally similar. Whereas normal subjects have ...
Stewart S F - - 1999
A rotating torus phantom was designed to assess the accuracy of color Doppler ultrasound. A thin rubber tube was filled with blood analog fluid and joined at the ends to form a torus, then mounted on a disk submerged in water and rotated at constant speeds by a motor. Flow ...
Chichilnisky E J - - 1999
Stimuli varying in intensity and chromaticity, presented on numerous backgrounds, were classified into red/green, blue/yellow and white/black opponent color categories. These measurements revealed the shapes of the boundaries that separate opponent colors in three-dimensional color space. Opponent color classification boundaries were generally not planar, but their shapes could be summarized ...
Barbur J L - - 1999
We show here that, in the absence of a direct geniculostriate input in human subjects, causing loss of sight in the visual half-field contralateral to the damage, the pupil responds selectively to chromatic modulation toward the long-wavelength (red) region of the spectrum locus even when the stimulus is isoluminant for ...
Blaser E - - 1999
An ambiguous motion paradigm, in which the direction of apparent motion is determined by salience (i.e., the extent to which an area is perceived as figure versus ground), is used to assay the amplification of color by attention to color. In the red-green colored gratings used in these experiments, without ...
Nagy A L - - 1999
The purpose of this study was to explore the interaction between achromatic information and chromatic information in a visual search task. It is widely accepted that signals in second stage color opponent mechanisms vary with both the luminance and chromaticity of a stimulus. However, detection experiments suggest a large degree ...
Pajevic S - - 1999
This paper investigates the use of color to represent the directional information contained in the diffusion tensor. Ideally, one wants to take into account both the properties of human color vision and of the given display hardware to produce a representation in which differences in the orientation of anisotropic structures ...
Farell B - - 1999
An isoluminant color grating usually appears to move more slowly than a luminance grating that has the same physical speed. Yet a grating defined by both color and luminance is seen as perceptually unified and moving at a single intermediate speed. In experiments measuring perceived speed and direction, it was ...
Olds E S - - 1999
Visual attention can be goal driven, stimulus driven, or a combination of the two. Here we report evidence for an unexpectedly stimulus-driven component of visual search for a target defined by color. Observers demonstrated a surprisingly cost-free ability to incorporate multiple classifiers in search for a target of one color ...
Chelette T - - 1999
Future helmet mounted systems and cockpit displays will rely on color graphics and information that high performance aircraft pilots will need to discern and understand. Color in displays may help reduce pilot workload. The effect of high G and reduced eye level blood pressure on field-of-view has been study extensively. ...
Noguchi H - - 1999
To investigate how illuminance and color temperature in illumination affect the autonomic nervous system and central nervous system in conditions tending to lower physiological activity, and with an ordinary residential setting in mind, we performed an experiment on 8 healthy male subjects. The experimental conditions consisted of 4 conditions provided ...
Wu P - - 1999
Spatial light modulation by use of a biphotonic holographic grating has been demonstrated in an azobenzene-doped polymer film. The mechanism of incoherent-to-coherent optical conversion originates from the photoinduced trans <--> cis isomerization of azobenzene molecules by two color lights. It is also found that when the intensity of the blue ...
Chawla D - - 1999
In a previous paper, we used fMRI to examine motion-sensitive responses in human area V5 as a function of stimulus speed. As predicted by electrophysiological findings, we observed optimal responses at intermediate speeds of around 7 to 30 degrees /s. These results revealed a nonlinear (inverted "U") dependency on speed ...
Rüttiger L - - 1999
The color of an object, when part of a complex scene, is determined not only by its spectral reflectance but also by the colors of all other objects in the scene (von Helmholtz, 1886; Ives, 1912; Land, 1959). By taking global color information into account, the visual system is able ...
Schirillo J A - - 1999
It has been hypothesized that to achieve color constancy, lightness judgments require an estimate of the illuminant. A companion paper [J. Opt. Soc. Am. A 16, 793 (1999)] suggests that surround articulation enhances the likelihood that a global luminance edge will be interpreted as being due to changes in illumination ...
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