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Ragulskis Minvydas - - 2007
Applicability of time-average moiré techniques for chaotic oscillations is analyzed in this paper. Envelope function characterizing the rate of convergence of time-averaged color intensity is derived. A study of the relationship among Lyapunov exponents and gray scale color intensity provides insight into the process of chaotic contrast modulation and confirms ...
Huang Liqiang - - 2007
Momentary awareness of a visual scene is very limited; however, this limitation has not been formally characterized. We test the hypothesis that awareness reflects a surprisingly impoverished data structure called a labeled Boolean map, defined as a linkage of just one feature value per dimension (for example, the color is ...
Westheimer Gerald - - 2007
Vision scientists long ago pointed to black and white as separate sensations and saw confirmation in the fact that in the absence of light, one perceives the visual field as gray against which the negative after-image of a bright light appeared blacker. The first recordings from optic nerve fibers in ...
Otaki Joji M - - 2007
It has been proposed that phenotypic plasticity and genetic assimilation through natural selection partly determine the direction of divergent selection that eventually results in speciation. To elucidate a process of butterfly color-pattern evolution and speciation in the light of this hypothesis, morphological and physiological differences between a pair of sister ...
Yuan Judy Chia-Chun - - 2007
STATEMENT OF PROBLEM: The natural tooth color space reported by a manufacturer may not represent the comprehensive spectrum of natural teeth for all population groups. PURPOSE: The purpose of this study was to define a natural tooth color space within the Greater Buffalo, New York population and to compare that ...
Mäthger Lydia M - - 2007
Cephalopods are known for their ability to change camouflage body patterns in response to changes in the visual background. Recent research has used artificial substrates such as checkerboards to investigate some specific visual cues that elicit the various camouflaged patterns in cuttlefish. In this study, we took information from experiments ...
Hillis James M JM Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. - - 2007
Are effects of background contrast on color appearance and sensitivity controlled by the same mechanism of adaptation? We examined the effects of background color contrast on color appearance and on color-difference sensitivity under well-matched conditions. We linked the data using Fechner's hypothesis that the rate of apparent stimulus change is ...
Pursiainen Otto L - - 2007
The production of high-quality low-defect single-domain flexible polymer opals which possess fundamental photonic bandgaps tuneable across the visible and near-infrared regions is demonstrated in an industrially-scalable process. Incorporating sub-50nm nanoparticles into the interstices of the fcc lattice dramatically changes the perceived color without affecting the lattice quality. Contrary to iridescence ...
Santos Nogueira Ana Carolina - - 2007
The aim of this study was to compare the susceptibility of hair with different melanin content (virgin white, blond and dark-brown) to photodegradation, evaluating changes on hair color and mechanical properties. Light exposure was carried out with a mercury-vapor lamp for up to 1800h. It was observed that color changes ...
Kuriki Ichiro - - 2007
One of the most challenging topics in the study of human color vision is the investigation of the number of hue-selective channels that are necessary for the representation of color appearance at the post-opponent level and the bandwidth of their sensitivity. The present study aims to elucidate this issue by ...
Stevens Martin - - 2007
Animals possess a range of defensive markings to reduce the risk of predation, including warning colours, camouflage, eyespots and mimicry. These different strategies are frequently considered independently, and with little regard towards predator vision, even though they may be linked in various ways and can be fully understood only in ...
Koralay Tamer - - 2008
Medium to large volume ignimbrites usually show vertical changes in terms of color, mineral components, texture and geochemistry. Determination of vertical changes in single extensive ignimbrite flow unit is difficult and requires careful studies. Color changes in ignimbrite flow units are very important for earth scientists. This may cause to ...
Mart?nez-Verd? Francisco - - 2007
We present a systematic algorithm capable of searching for optimal colors for any lightness L* (between 0 and 100), any illuminant (D65, F2, F7, F11, etc.), and any light source reported by CIE. Color solids are graphed in some color spaces (CIELAB, SVF, DIN99d, and CIECAM02) by horizontal (constant lightness) ...
Huang Kuo-Chen - - 2007
Two experiments assessed the effects of colored light, color of a comparison stimulus, and illumination on error in perceived depth with binocular and monocular vision. Exp. 1 assessed effects of colored light, color of comparison stimulus, and source of depth cues on error in perceived depth. A total of 29 ...
Wannig Aurel - - 2007
In the visual system, early atomized representations are grouped into higher-level entities through processes of perceptual organization. Here we present neurophysiological evidence that a representation of a simple object, a surface defined by color and motion, can be the unit of attentional selection at an early stage of visual processing. ...
Gheorghiu Elena - - 2007
We investigated whether contour-shape processing mechanisms are selective for color direction using the shape-frequency and shape-amplitude after-effects, or SFAE and SAAE [Gheorghiu, E. & Kingdom, F. A. A. (2006). Luminance-contrast properties of contour-shape processing revealed through the shape-frequency after-effect. Vision Research, 46(21), 3603-3615. Gheorghiu, E. & Kingdom, F. A. A. ...
Vanleeuwen M T - - 2007
Color constancy is one of the most impressive features of color vision systems. Although the phenomenon has been studied for decades, its underlying neuronal mechanism remains unresolved. Literature indicates an early, possibly retinal mechanism and a late, possibly cortical mechanism. The early mechanism seems to involve chromatic spatial integration and ...
Bennett Eric P - - 2007
We present a technique for enhancing underexposed visible-spectrum video by fusing it with simultaneously captured video from sensors in nonvisible spectra, such as Short Wave IR or Near IR. Although IR sensors can accurately capture video in low-light and night-vision applications, they lack the color and relative luminances of visible-spectrum ...
Laeng Bruno - - 2007
Extreme natural ambient light reduction, in both energy and range of wavelength spectrum, occurs during the winter season at very high latitudes (above the Arctic Circle or 66 degrees 32' North) that in turn results in increased exposure to artificial lighting. In contrast, during the summer months, the sun remains ...
Mäthger Lydia M - - 2007
Nature's best-known example of colorful, changeable, and diverse skin patterning is found in cephalopods. Color and pattern changes in squid skin are mediated by the action of thousands of pigmented chromatophore organs in combination with subjacent light-reflecting iridophore cells. Chromatophores (brown, red, yellow pigment) are innervated directly by the brain ...
Jiang Yi - - 2007
When two isoluminant colors alternate at frequencies of 25 Hz or higher, observers perceive only one fused color. Chromatic flicker beyond the fusion frequency induces flicker adaptation in human observers and stimulates monkey V1 neurons. Here we use functional magnetic resonance imaging (fMRI) to show that many human visual cortical ...
Vierck Esther - - 2007
Two of the possible mechanisms that have been put forward to explain precuing effects are signal enhancement and uncertainty reduction. Signal enhancement leads to processing advantages for valid information because the signal at the known input channel is enhanced, whereas uncertainty reduction allows observers to ignore confusing distractor items in ...
Sampath Sheela - - 2008
OBJECTIVES: The main objectives were: (1) To find out the light transmittance characteristics of fiber-reinforced composites. (2) Determination of color differences between non-fiber-reinforced composites and fiber-reinforced composites. (3) Investigation of relationship between light transmittance and color. METHODS: A commercial microhybrid composite was reinforced with S-type braided glass fibers. The samples ...
Moreno Ivan - - 2007
We describe a fully-analytical, simple yet sufficiently accurate method to compute the color pattern of the light emitted from multicolor light-emitting diode (LED) assemblies. Spatial distributions for both color variation and correlated color temperature (CCT) as a function of typical parameters of influence, such as LED spectrum, spatial distribution of ...
Yoshioka Shinya - - 2007
It is well known that the wing scales of butterflies and moths have elaborated microstructures that cause various optical effects. Structural colors occur when the microstructures have a size comparable with the wavelength of light. On the other hand, the wing scales of some species are structurally modified at a ...
Tsai Luo-Wei - - 2007
This paper presents a novel vehicle detection approach for detecting vehicles from static images using color and edges. Different from traditional methods, which use motion features to detect vehicles, this method introduces a new color transform model to find important "vehicle color" for quickly locating possible vehicle candidates. Since vehicles ...
Mathes Birgit - - 2007
Contour integration perceptually links together similarly oriented line elements hidden between randomly oriented distracters. To investigate how contour integration depends on early sensory processing, we compared the electrophysiological correlate of contour integration of elements defined by luminance (black-and-white) or isoluminant color (red-and-green) contrasts. Detection performance for color- and luminance-defined contours ...
Borgia Gerald - - 2007
How the displays of bowerbirds have evolved has attracted widespread interest. Endler et al. (2005) analyzed color use in display in a subset of bowerbird species and generalized their results to all bowerbirds. Here we discuss problems with their analysis that calls into question their conclusions. For example, they state ...
Wu Wen-Yen - - 2007
Various colors have been used as visual cues to trap insect pests. For example, yellow traps for monitoring and control of the oriental fruit fly (Bactrocera dorsalis) have been in use for a very long time. However, the chromatic cue of using color traps has never been meticulously investigated. In ...
Nishida Shin'ya - - 2007
Whether fundamental visual attributes, such as color, motion, and shape, are analyzed separately in specialized pathways has been one of the central questions of visual neuroscience. Although recent studies have revealed various forms of cross-attribute interactions, including significant contributions of color signals to motion processing, it is still widely believed ...
Odaba┼či A Z - - 2007
The color of eggshells from eggs laid by commercial-type Hy-Line brown hens 25 wk of age was studied over a period of 10 mo. Color measurements were made by a color machine vision system and were analyzed using a mixed model to calculate between and within hen variances and to ...
Kyllingsbaek Søren - - 2007
Observers given brief exposures of pairs of colored bars and asked to report both the color and the orientation of each bar showed evidence of stochastic independence between reports of the 4 features (2 colors and 2 orientations). The authors also found virtually perfect stochastic independence between reports of colors ...
Heidary Kaveh - - 2007
The goal of discrimination of one color from many other similar-appearing colors even when the colored objects show substantial variation or noise is of obvious import. We show how to accomplish that using a technique called Margin Setting. It is possible not only to have very low error rates but ...
Schoenfeld M A - - 2007
The cortical mechanisms of feature-selective attention to color and motion cues were studied in humans using combined electrophysiological, magnetoencephalographic, and hemodynamic (functional magnetic resonance imaging) measures of brain activity. Subjects viewed a display of random dots that periodically either changed color or moved coherently. When attention was directed to the ...
Hansen Thorsten - - 2007
Color constancy is the ability to assign a constant color to an object independent of changes in illumination. Color constancy is achieved by taking context information into account. Previous approaches that have used matching paradigms to quantify color constancy found degrees of constancy between 20% and 80%. Here, we studied ...
Kemp Darrell J - - 2007
Structural colors result from an interaction between light and the fine-scale physical structure of a surface, and are often extremely bright, chromatic, and iridescent. Given that these visual features depend upon the aggregate abundance and architectural precision of photonic structures, structurally colored sexual ornaments seem well placed to indicate a ...
Ruppertsberg Alexa I - - 2007
We present a numerical analysis of rendered pairs of rooms, in which the spectral power distribution of the illuminant in one room matched the surface reflectance function in the other room, and vice versa. We ask whether distinction between the rooms is possible and on what cues this discrimination is ...
Martin Schaefer H - - 2007
Reproduction in plants often requires animal vectors. Fruit and flower colors are traditionally viewed as an adaptation to facilitate detection for pollinators and seed dispersers. This longstanding hypothesis predicts that fruits are easier to detect against their own leaves compared with those of different species. We tested this hypothesis by ...
Kopp Bruno - - 2007
BACKGROUND: Decision-making is a fundamental capacity which is crucial to many higher-order psychological functions. We recorded event-related potentials (ERPs) during a visual target-identification task that required go-nogo choices. Targets were identified on the basis of cross-dimensional conjunctions of particular colors and forms. Color discriminability was manipulated in three conditions to ...
Sanz Cervera Susana - - 2007
The impact of lighting on minimally processed cauliflower packaged in 4 different film types (PVC and 3 P-Plus) has been measured and quantified. The effect on the sensorial quality of storage at 4 degrees C in darkness and partial or continuous lighting was evaluated. The gas concentrations in the packages ...
Arikawa Hiroyuki - - 2007
The purpose of this investigation was to examine the effect of filler particle size and shape as well as filler content on light transmittance characteristics and color of experimental composite resins. A mixture of 30 mol% Bis-GMA and 70 mol% TEGDMA was prepared as a base monomer and to which ...
Rowe Mickey P - - 2007
X-linked photopigment polymorphism produces six different color vision phenotypes in most species of New World monkey. In the subfamily Callitrichinae, the three M/L alleles underlying these different phenotypes are present at unequal frequencies suggesting that selective pressures other than heterozygous-advantage operate on these alleles. Earlier we investigated this hypothesis with ...
Werner Annette - - 2007
Color constancy refers to our remarkable ability to perceive the color of objects nearly constant despite considerable changes in the spectral content of the illumination. As such it is most important for object recognition. Visual motion can make object recognition harder because it limits the viewing time and increases the ...
Delhey Kaspar - - 2007
Colorful plumages are conspicuous social signals in birds, and the expression of these colors often reflects the quality of their bearers. Since mature feathers are dead structures, plumage color is often considered a static signal that does not change after molt. Feathers, however, can and do deteriorate between molts, and ...
Watanabe Junji - - 2007
For rapid alternations of two colors (e.g., red and green), human observers see the mixed color (yellow). This chromatic flicker fusion has been considered to reflect neural integration of color signals presented successively at the same retinal location. If so, the retinal alternation rate should be a critical fusion parameter. ...
Cole Barry L - - 2006
PURPOSE: Past investigations of the ability of people with color vision deficiency (CVD) to name the colors of surface colors have been occupation-specific. This study was undertaken as a more generalized investigation to explore particularly the effects of stimulus size and shape. METHODS: One hundred CVD observers and 20 color ...
Stavenga Doekele G - - 2006
Butterfly eyes consist of three types of ommatidia, which are more or less randomly arranged in a spatially regular lattice. The corneal nipple array and the tapetum, optical structures that many but not all butterflies share with moths, suggest that moths are ancestral to butterflies, in agreement with molecular phylogeny. ...
González-Tomás L - - 2006
Consumers' perceptions of the color and texture of 8 commercial vanilla dairy desserts were studied and related to color and rheological measurements. First, the 8 desserts were evaluated by a group of consumers by means of the Free Choice Profile. For both color and texture, a 2-dimensional solution was chosen, ...
Curd Francis M - - 2006
STATEMENT OF PROBLEM: Shade selection is affected by a host of variables, including lighting. PURPOSE: The purpose of this study was to assess the ability of dental students to match shades under natural lighting and using a light-correcting device, specifically to determine whether there are differences based on: (1) year ...
Waitt Corri - - 2006
The use of photographs, slides, computerized images, and video to study behavior is increasingly being employed in nonhuman primates. However, since these mediums have been designed to simulate natural coloration for normal trichromatic human vision, they can fail to reproduce color in meaningful and accurate ways for viewers with different ...
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