The CIE (2012) 10-deg “physiologically-relevant” , , and chromaticity coordinates are related to the CIE (2012) 10-deg , and CMFs by:
where, , and are the chromaticity coordinates, and , and are the CMFs.
The , and CMFs are linear transformations of the cone fundamentals according to:
where , and are the Stockman & Sharpe (2000) or CIE (2006) 10-deg cone fundamentals tabulated here.
The proposed CIE standard is also much concerned about defining the precision of the CMFs. Thus, the coefficients of the transformation are defined to 8 decimal places (as in the equations above), the CMFs themselves are calculated from the cone fundamentals given in linear (energy) units to 9 sf (given here), and the results in linear (energy) units are tabulated to 7 significant figures. Finally, the chromaticity coordinates are defined to 5 dp.
The functions are provided here at 0.1, 1 and 5 nm steps.
Please note that these are proposals that have yet to be ratified by the full TC 1-36 committee or the CIE.
Stockman, A., & Sharpe, L. T. (2000). Spectral sensitivities of the middle- and long-wavelength sensitive cones derived from measurements in observers of known genotype. Vision Research, 40, 1711-1737.
CIE (2006). Fundamental chromaticity diagram with physiological axes. Parts 1 and 2. Technical Report 170-1. Vienna: Central Bureau of the Commission Internationale de l' Éclairage.