EN ISO/CIE 11664-5:2024 PDF

Overview

EN ISO/CIE 11664-5:2024 is an international standard published by CEN, specifying the calculation methods for the CIE 1976 L*u*v* colour space and the u', v' uniform chromaticity scale diagram. This standard plays a vital role in the precise and consistent characterization of color, particularly when evaluating color differences as perceived by the human eye. By providing uniform and repeatable protocols for calculating color coordinates and differences, EN ISO/CIE 11664-5:2024 supports quality assurance, product development, and regulatory compliance across industries where accurate color measurement is essential, such as paints, textiles, display technologies, and digital imaging.

Key Topics

• CIE 1976 L*u*v* Colour Space (CIELUV): Defines a three-dimensional, approximately uniform colour space for visual uniformity in color measurement, supporting correlates of lightness, chroma, saturation, and hue.

• u', v' Uniform Chromaticity Scale (UCS) Diagram: Specifies how to compute coordinates for a perceptually linear chromaticity diagram, facilitating better color comparison.

• Euclidean Distance Methods: Establishes two methods for calculating color differences in the L*u*v* space, representing the perceived magnitude between color stimuli.

• Tristimulus Values: Focuses on tristimulus values from the CIE 1931 (2° observer) or CIE 1964 (10° observer) standard colorimetric systems as the basis for further color space calculations.

• Scope Limitations: Applicable to reflecting or transmitting objects and self-luminous displays simulating object colors (with proper normalization). It does not generally apply to stimuli perceived as direct light sources, except for the UCS diagram and hue/saturation correlates.

Applications

The EN ISO/CIE 11664-5:2024 standard is widely applicable in fields where assessing color differences, color rendering, and color quality is critical:

• Paints, Coatings, and Varnishes: Ensures consistent color specifications and reliable product quality by standardizing how color differences are quantified.

• Textiles and Plastics: Facilitates objective color matching and batch-to-batch consistency.

• Display Technology: Used in calibrating and evaluating self-luminous displays (televisions, monitors, smartphones) when simulating real-world object colors.

• Lighting Industry: Supports the assessment of color rendering, especially for products and environments where color appearance under specific light conditions is essential.

• Digital Imaging and Printing: Assists with color management workflows by providing a common reference for color comparison.

• Quality Control: Enables precise color comparison and the setting of acceptance thresholds in manufacturing and laboratory environments.

Related Standards

EN ISO/CIE 11664-5:2024 is part of a broader family of international standards on colorimetry, ensuring coherence across various stages of color evaluation and measurement:

• EN ISO/CIE 11664-1: CIE standard colorimetric observers
• EN ISO/CIE 11664-2: CIE standard illuminants
• EN ISO/CIE 11664-3: CIE tristimulus values
• EN ISO/CIE 11664-4: CIE 1976 L*a*b* colour space
• EN ISO/CIE 11664-6: CIEDE2000 colour-difference formula

Adherence to these standards supports the interoperability of equipment, consistency of measurement, and comparability of results worldwide.

Keywords: CIE 1976 L*u*v* colour space, uniform chromaticity scale diagram, color difference formula, color measurement standard, colorimetry, tristimulus values, CEN, ISO/CIE 11664-5:2024, color quality control.