ASTM E308-15
Standard Practice for Computing the Colors of Objects by Using the CIE System

Standard No.

ASTM E308-15

Release Date

2015

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM E308-17

Latest

ASTM E308-22

Scope

5.1 The CIE colorimetric systems provide numerical specifications that are meant to indicate whether or not pairs of color stimuli match when viewed by a CIE standard observer. The CIE color systems are not intended to provide visually uniform scales of color difference or to describe visually perceived color appearances.

5.2 This practice provides for the calculation of tristimulus values X, Y, Z and chromaticity coordinates x, y that can be used directly for psychophysical color stimulus specification or that can be transformed to nearly visually uniform color scales, such as CIELAB and CIELUV. Uniform color scales are preferred for research, production control, color-difference calculation, color specification, and setting color tolerances. The appearance of a material or an object is not completely specified by the numerical evaluation of its psychophysical color, because appearance can be influenced by other properties such as gloss or texture.

1.1 This practice provides the values and practical computation procedures needed to obtain CIE tristimulus values from spectral reflectance, transmittance, or radiance data for object-color specimens.

1.2 Procedures and tables of standard values are given for computing from spectral measurements the CIE tristimulus values X, Y, Z, and chromaticity coordinates x, y for the CIE 1931 standard observer and X₁₀, Y₁₀, Z₁₀ and x₁₀. y₁₀ for the CIE 1964 supplementary standard observer.

1.3 Standard values are included for the spectral power of six CIE standard illuminants and three CIE recommended fluorescent illuminants.

1.4 Procedures are included for cases in which data are available only in more limited wavelength ranges than those recommended, or for a measurement interval wider than that recommended by the CIE. This practice is applicable to spectral data obtained in accordance with Practice E1164 with 1-, 5-, 10-, or 20-nm measurement interval.

1.5 Procedures are included for cases in which the spectral data are, and those in which they are not, corrected for bandpass dependence. For the uncorrected cases, it is assumed that the spectral bandpass of the instrument used to obtain the data was approximately equal to the measurement interval and was triangular in shape. These choices are believed to correspond to the most widely used industrial practice.

1.6 This practice includes procedures for conversion of results to color spaces that are part of the CIE system, such as CIELAB and CIELUV (3). Equations for calculating color differences in these and other systems are given in Practice D2244.

1.7 The values s......

ASTM E308-15 Referenced Document

• ASTM D2244 Standard Test Method for Calculation of Color Differences From Instrumentally Measured Color Coordinates
• ASTM E1164 Standard Practice for Obtaining Spectrophotometric Data for Object-Color Evaluation
• ASTM E2022 Standard Practice for Calculation of Weighting Factors for Tristimulus Integration
• ASTM E2729 Standard Practice for Rectification of Spectrophotometric Bandpass Differences
• ASTM E284 Standard Terminology of Appearance
• ASTM E313 Standard Practice for Calculating Yellowness and Whiteness Indices from Instrumentally Measured Color Coordinates

ASTM E308-15 history

• 2022 ASTM E308-22 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 2018 ASTM E308-18 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 2017 ASTM E308-17 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 2015 ASTM E308-15 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 2013 ASTM E308-13 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 2012 ASTM E308-12 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 2008 ASTM E308-08 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 2006 ASTM E308-06 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 2001 ASTM E308-01 Standard Practice for Computing the Colors of Objects by Using the CIE System
• 1999 ASTM E308-99 Standard Practice for Computing the Colors of Objects by Using the CIE System