What is ISO/CIE 11664-4- CIE 1976 L*a*b* color space about?
ISO/CIE 11664-4 is the part 4 of a multi-series standard about safety standard on colorimetry.
ISO/CIE 11664-4 specifies a method of calculating the coordinates of the CIE 1976 L*a*b* colour space, including correlates of lightness, chroma, and hue. ISO/CIE 11664-4 includes two methods for calculating Euclidean distances in this space to represent the perceived magnitude of color differences. ISO/CIE 11664-4 is applicable to tristimulus values calculated using color-matching functions of the CIE 1931 standard colorimetric system or the CIE 1964 standard colorimetric system.
ISO/CIE 11664-4 is used for the specification of color stimuli perceived as belonging to a reflecting or transmitting object, where a three‑dimensional space more uniform than tristimulus space is required. ISO/CIE 11664-4 is applicable to self‑luminous displays, such as cathode ray tubes, if they are being used to simulate reflecting or transmitting objects and if the stimuli are appropriately normalized. Calculating the reverse transformation is shown in ISO/CIE 11664-4.
NOTE 1: ISO/CIE 11664-4 does not cover more sophisticated color-difference formulae based on CIELAB, such as the CMC formula, the CIE94 formula, the DIN99 formula, and the CIEDE2000 formula, nor does it cover the alternative uniform color space, CIELUV.
NOTE 2: ISO/CIE 11664-4 does not apply to color stimuli perceived as belonging to an area that appears to be emitting light as a primary light source, or that appears to be specularly reflecting such light.
Who is ISO/CIE 11664-4- CIE 1976 L*a*b* color space for?
ISO/CIE 11664-4 on CIE 1976 L*a*b* color space is relevant to:
- Manufacturers of colorimeter
- Manufacturers of L*a*b* calculators
- Textile industries
- Food industries
- Manufacturers of paint
- Manufacturers of color spectrometer
Why should you use ISO/CIE 11664-4- CIE 1976 L*a*b* color space?
The three‑dimensional color space produced by plotting CIE tristimulus values (X, Y, Z) in rectangular coordinates is not visually uniform, nor is the (x,y,Y) space nor the two‑dimensional CIE (x,y) chromaticity diagram. Equal distances in these spaces do not represent equally perceptible differences between color stimuli. For this reason, in 1976, the CIE introduced and recommended two new spaces (known as CIELAB and CIELUV) whose coordinates are nonlinear functions of X, Y, and Z.
The purpose of ISO/CIE 11664-4 is to define procedures for calculating the coordinates of the CIE 1976 L*a*b* (CIELAB) color space and the Euclidean color difference values based on these coordinates.
Overall, ISO/CIE 11664-4 is useful as it aids on CIE 1976 L*a*b* (CIELAB), which is one of the most popular color spaces for measuring object colors.
What’s changed since the last update?
BS EN ISO/CIE 11664-4:2019 supersedes EN ISO 11664-4:2011.
BS EN ISO/CIE 11664-4:2019 replaces ISO 11664-4:2008 | CIE S 014-3:2011, of which it constitutes a minor revision.
