- Industry: Education
- Number of terms: 1674
- Number of blossaries: 1
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The University of Illinois at Chicago (UIC) is a public university located on three urban campuses in Chicago. UIC ranks in the top 50 US institutions with strong research programs. The university boasts one of the largest medical schools in the US and operates Illinois’ major public medical center ...
A member of a minimal set of stimuli (usually lights), mixtures of the elements of which are capable of matching all colors. For normal human beings three primaries are sufficient to provide a perceptual match. There are indefinitely many sets of three primaries, mixtures of which are capable of matching all colors. For colorimetric purposes the concept of a primary has been extended to include "imaginary" primaries-ones that are not physically realizable. Thus the CIE standard observer makes use of imaginary primaries. The results of mixing imaginary primaries are derived from data using real lights.
Industry:Physics
A standard test for deficiencies of color vision in which the subject is asked to arrange a set of 100 colored chips in circle. Subjects with normal color vision will arrange the chips in a specific order with very few deviations. Subjects with abnormal color vision will deviate from the normal arrangement in ways that provide information about the nature of their defect.
Industry:Physics
A function from wavelength to the smallest discriminable difference in wavelength. Human wavelength discrimination varies substantially across the spectrum and although performance varies considerably with testing conditions the resulting curve is typically quite complex. The wavelength discrimination function is an important source of information about the contributions of the different cone types to color vision.
Industry:Physics
An international organization that recommends standards and procedures for light and lighting, including colorimetry.
Industry:Physics
A widely used system for describing the color appearance of samples. The Munsell system uses matching against a set of samples and interpolation between them to arrive at a designator for the appearance of a given test sample. Color appearance in the Munsell system is characterized using sets of three symbols, for example 2. 5 YR 5/10. 2. 5 YR is the hue, 5/ the value (= lightness), and /10 the chroma.
Industry:Physics
Condition of possessing three independent channels for conveying color information, derived from the three different cone types. A single set of three appropriately chosen primaries is sufficient to match the color appearance of any stimulus for a trichromat. Normal human color vision is trichromatic, but some other organisms, e.g. pigeons, have tetrachromatic color vision: they require sets of four primaries to produce complete color matches. Other organisms and some color deficient human beings are dichromats: they require only sets of two primaries to produce complete color matches.
Industry:Physics
A set of tri-stimulus values for spectral lights that is designed to allow a standard and objective way of describing the color matching properties of different lights. Although very few people will accept all the color matches of the Standard Observer, lights that are matches for the Standard Observer will be near matches for most people with normal color vision. Since the matching properties of stimuli vary with size and other features of the viewing conditions there is more than one Standard Observer.
Industry:Physics
The power of a light, often weighted by the spectral sensitivity of the eye. Since the eye is much more sensitive to light of some wavelengths than it is to others, two monochromatic lights can have equal power, while one appears dim and the other appears bright. Visual scientists often use a system of units (photometric units) that scale the physical power (given in radiometric units) to the sensitivity of the eye at each wavelength.
Industry:Physics
A color match between physically different stimuli, i.e. a match between stimuli with different reflectances or spectral power distributions. Such stimuli that match (for an observer and a viewing condition) are metamers (with respect to that observer and that viewing condition).
Industry:Physics
