(redirected from lab)
Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Idioms, Wikipedia.


A color space defined by the Commission Internationale de l'Eclairage (see CIE). In 1931, CIE defined the CIE XYZ color space, which represented all possible colors based on human perception. Like RGB, CIE XYZ has three orthogonal dimensions; however, X, Y and Z do not correspond to real colors. They are simply mathematically convenient with Y carrying the luminance information. CIE is usually represented by a 2D "chromaticity diagram" obtained from the CIE XYZ model.

The CIE XYZ model and chromaticity diagram are not perceptually uniform. A more uniform version of CIE was defined in 1976, officially known as CIE L*a*b*. L* stands for luminance, a* is the red-green axis, and b* is the blue-yellow axis. The asterisks were added to differentiate CIE from another L,a,b model.

A Reference and Intermediary
Although CIE L*a*b* has a large color gamut and is considered the most accurate color model, it is often used as a reference only or as an intermediary for color space conversion. In practice, the RGB and CMYK color spaces are more widely used for display and printing, and HSB and HSL are used for color selection. However, all color spaces, including RGB, CMYK, HSB, HSL and YUV, are subsets of the entire human color gamut as measured and defined by CIE. See color space, RGB, CMYK, YUV, HSB and HSL.

CIE 1976 Chromaticity Diagram
In the original 1931 CIE diagram, the color green seemed to dominate. In 1976, changes were made that displayed perceived colors more uniformly. (Image courtesy of Photo Research, Inc.,
References in periodicals archive ?
Anderson, who lives in a mobile-home park downhill from the lab.
Each lab is equipped with the necessary safety devices for all the sciences, including fume hoods, showers and eyewash stations.
Some cases that come to the lab have straightforward solutions, such as a mysterious group of dead eagles.
The table includes lab means, deviations from the grand mean and comparative performance values (CPVs) for each sample.
The health department has the power to order labs that fail to meet accuracy standards to stop performing tests, and, if necessary, it can close a lab altogether.
In the years following, researchers found higher than average rates of bladder cancer in the West Hills and Chatsworth neighborhoods close to the lab, and higher than normal rates of lung and other cancers.
We're finding smaller labs in residential areas, light industrial areas, storage lots, trailers, motels, hotel rooms - things where you can bring all your equipment and fit it in one small room,'' said Greg Smith, the assistant director of Los Angeles Interagency Metropolitan Police Apprehension Crime Task Force.
The lab also failed a proficiency test and an on-site inspection.
But the county crime lab continued to do breath testing for nearly two months after March 19, a decision since justified by citing Larson's statement.
Defense attorneys, in a motion filed two weeks ago, demanded prosecutors be disqualified on grounds they cannot be impartial and have an obvious interest in how the crime lab issues are resolved.