Search results for "Colour contrast"

showing 3 items of 3 documents

Colour Constancy in Goldfish and Man: Influence of Surround Size and Lightness

2002

Colour constancy was investigated by using a series of 10 simultaneously presented surface colours ranging in small steps from green through gray to red – purple. Goldfish were trained to select one medium test field when the entire setup was illuminated with white light. In the tests, either red or green illumination was used. Colour constancy, as inferred from the choice behaviour, was perfect under green illumination when the test fields were presented on a gray or a white background, but imperfect on a black background. Under red illumination and a white background, however, colour constancy was overcompensated. Here, a colour contrast effect was observed. The influence of background l…

AdultMaleExperimental and Cognitive PsychologyLuminance050105 experimental psychologyContrast Sensitivity03 medical and health sciences0302 clinical medicineOpticsArtificial IntelligenceGoldfishPsychophysicsCarassius auratusWhite lightAnimalsHumans0501 psychology and cognitive sciencesMathematicsColor constancybusiness.industry05 social sciencesSensory SystemsOphthalmologyFemaleColour contrastbusinessColor PerceptionPhotic Stimulation030217 neurology & neurosurgeryPerception
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<title>The perception of isoluminant coloured stimuli of amblyopic eye and defocused eye</title>

2008

In routine eye examination the visual acuity usually is determined using standard charts with black letters on a white background, however contrast and colour are important characteristics of visual perception. The purpose of research was to study the perception of isoluminant coloured stimuli in the cases of true and simulated amlyopia. We estimated difference in visual acuity with isoluminant coloured stimuli comparing to that for high contrast black-white stimuli for true amblyopia and simulated amblyopia. Tests were generated on computer screen. Visual acuity was detected using different charts in two ways: standard achromatic stimuli (black symbols on a white background) and isoluminan…

Visual acuityVisual perceptiongenetic structuresmedia_common.quotation_subjectLuminanceeye diseaseslaw.inventionAchromatic lenslawPerceptionmedicineContrast (vision)Optometrymedicine.symptomColour contrastRoutine eye examinationPsychologymedia_commonSPIE Proceedings
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Howard–Dolman stereovision test at different opponent colour stimuli

2011

The purpose of this study was to investigate visual depth perception of real physical colour stimuli with red-green and blue-yellow opponency. We modified the Howard–Dolman stereotest where subjects should determine the closer of two bars emitting the light of definite colour placed in front of a CRT monitor served as colour background. Two-alternative forced-choice paradigms were used to determine depth perception threshold values. Thresholds close to 5–10 arcsec for luminance and colour contrast stimuli were revealed both for red-green and blue-yellow stimuli. A term, stereosensitivity – a reciprocal magnitude of the stereothreshold – was introduced to separately analyse luminance and col…

genetic structuresbusiness.industrymedia_common.quotation_subjectCrt monitorLuminanceAtomic and Molecular Physics and OpticsStereopsisOpticsContrast (vision)Computer visionVisual depth perceptionArtificial intelligenceColour contrastDepth perceptionbusinessmedia_commonMathematicsJournal of Modern Optics
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