DIN EN ISO 11664-5:2017-01

This part of ISO/CIE 11664 specifies the method of calculating the coordinates of the CIE 1976 L*u*v* colour space including correlates of lightness, chroma, saturation and hue. It includes two methods for calculating Euclidean distances in this space to represent the relative perceived magnitude of colour differences. It also specifies the method of calculating the coordinates of the u',v' uniform chromaticity scale diagram. This part of ISO/CIE 11664 is applicable to tristimulus values calculated using the colour-matching functions of the CIE 1931 standard colorimetric system or the CIE 1964 standard colorimetric system. This part of ISO/CIE 11664 may be used for the specification of colour stimuli perceived as belonging to a reflecting or transmitting object, where a three-dimensional space more uniform than tristimulus space is required. This includes self-luminous displays, like cathode ray tubes, if they are being used to simulate reflecting or transmitting objects and if the stimuli are appropriately normalized. This part of ISO/CIE 11664, as a whole, does not apply to colour 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. Only the u',v' uniform chromaticity scale diagram defined in this standard and the correlates of hue and saturation apply to such colour stimuli. This standard (EN ISO 11664-5:2016) contains the German translation of the International Standard ISO/CIE 11664-5:2016, which has been prepared by the "International Commission on Illumination". At the international level the responsible committee is Technical Committee ISO/TC 274 "Light and lighting" and at the European level Technical Committee CEN/TC 139 "Paints and varnishes" (secretariat: DIN, Germany). The responsible national committee is NA 025-00-02 GA "Gemeinschaftsarbeitsausschuss FNF/FNL: Farbmetrik" ("Joint Working Committee FNF/FNL: Colometry") at DIN Standards Committee Colour (FNF).