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At least 19 recordsLinked to original sources
PubMed2001

Illuminant cues in surface color perception: tests of three candidate cues.

Many recent computational models of surface color perception presuppose information about illumination in scenes. The models differ primarily in the physical process each makes use of as a cue to the illuminant. We evaluated whether the human visual system makes use of any of three of the following candidate illuminant cues: (1) specular highlight, (2) full surface specularity [Lee, H. C. (1986). Method for computing the scene-illuminant chromaticity from specular highlights. Journal of the Optical Society of America A, 3(10), 1694-1699; D'Zmura, M., & Lennie, P. (1986). Mechanisms of color constancy. Journal of the Optical Society of America A, 3(10), 1662-1672], and (3) uniform background. Observers viewed simulated scenes binocularly in a computer-controlled Wheatstone stereoscope. All simulated scenes contained a uniform background plane perpendicular to the observer's line of sight and a small number of specular, colored spheres resting on the uniform background. Scenes were rendered under either standard illuminant D65 or standard illuminant A. Observers adjusted the color of a small, simulated test patch to appear achromatic. In a series of experiments we perturbed the illuminant color signaled by each candidate cue and looked for an influence of the changed cue on achromatic settings. We found that the specular highlight cue had a significant influence, but that the influence was asymmetric: greater when the base illuminant, CIE standard Illuminant A, was perturbed in the direction of Illuminant D65 than vice versa. Neither the full surface specularity cue nor the background cue had any observable influence. The lack of influence of the background cue is likely due to the placement of the test patch in front of the background rather than, as is typical, embedded in the background.

Color Perception↗
PubMed1977

[Importance, especially in aeronautics, of color perception tests under dynamic conditions. Study of a suitable experimental apparatus].

Following a review of the most recent opinion on the physiology of colour vision, a device for examining it in dynamic, i.e. real-life conditions is described. The apparatus consist of two projectors which flash two absolutely identical pictures on to the screen, one of them is upside down. It appears at fixed but adjustable intervals so that the exposure time of the intelligible image can be varied. Subjects were also controlled with Ishihara charts and Nägel anomaloscope. The results are compared and point to the higher sensitivity of the dynamic test to even slight degrees of dyschromatopsia.

Color Perception Tests↗
PubMed2004

[The analysis of refractive error in children and adolescents from 6-15 years of age based on 1000 examinations in two major Polish regions].

PURPOSE: The aim of this study is to present the results of screening examinations of refractive errors, taken on 1002 of school children ranging from 6 to 15 years of age. MATERIAL AND METHODS: As the result of Internet screening visual acuity and color perception tests named "I can see..." in 10,021 children from randomly chosen schools in Poland in the year 2002, the group of 1002 children was chosen. In this group, the subjective and objective refractive error examination was taken as well as the visual acuity test, color perception with the use of Ishihara tables and full ophthalmologic examination. RESULTS: Average visual acuity was RE: 0.72 (SD +/- 0.31) and LE: 0.72 (SD +/- 0.31). The prevalence of emmetropia was 34%. In the examined group myopia in 17%, hyperopia in 20%, astigmatism in 5.5% of children was found, and in 24.5% of patients complex errors occur such as myopic and hyperopic astigmatism.

Adolescent↗