What is ISO 11664-6- Colorimetry about?
ISO 11664-6 is a safety standard on Colorimetry.
ISO 11664-6 specifies the method of calculating colour differences according to the CIEDE2000 formula. ISO 11664-6 is applicable to input values of CIELAB L*, a*, b* coordinates calculated according to ISO 11664-4:2008(E)/CIE S 014-4/E:2007.
ISO 11664-6 may be used for the specification of the colour difference between two colour stimuli perceived as belonging to reflecting or transmitting objects. ISO 11664-6 includes displays, if they are being used to simulate reflecting or transmitting objects and if the tristimulus values representing the stimuli are appropriately normalized.
Note: ISO 11664-6 does not apply to colour stimuli perceived as belonging to areas that are emitting light as primary light sources, or that are secularly reflecting such light.
Who is ISO 11664-6- Colorimetry for?
ISO 11664-6 on colorimetry is relevant to:
- Manufacturers of colorimeter
- Chemical engineers
- Colour printing, textile manufacturing, paint manufacturing, and food industries
Why should you use ISO 11664-6- Colorimetry?
The three-dimensional colour 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 and diagrams do not represent equally perceptible differences between colour stimuli. For this reason, the CIE has standardized two more-uniform colour spaces (known as CIELAB and CIELAV) whose coordinates are non-linear functions of X, Y, and Z. Numerical values representing the relative magnitude of colour differences are described by simple Euclidean distances in these spaces or by more sophisticated colour-difference formulae that improve the correlation with the relative perceived size of differences. The purpose of ISO 11664-6 is to define one such formula, the CIEDE2000 formula. ISO 11664-6 is based on CIE Technical Report 142-2001. The formula is an extension of the CIE 1976 L*a*b* colour-difference formula (ISO 11664- 4:2008(E)/CIE S 014-4/E:2007) with corrections for variation in colour-difference perception dependent on lightness, chroma, hue, and chroma-hue interaction. Reference conditions define material and viewing environment characteristics to which the formula applies.
Overall, ISO 11664-6 is useful as it provides guidance on the experimental observation and material variables that can have parametric effects that influence the visual colour-difference results (CIE, 1993).
