## RGB colour space

### Source

Figure 6 from
Stockman, A. (2004). Colorimetry. In T. G. Brown, K. Creath, H. Kogelnik, M. A. Kriss, J. Schmit & M. J. Weber (Eds.), *The Optics Encyclopedia: Basic Foundations and Practical Applications (Vol. 1, pp. 207-226).* Berlin: Wiley-VCH.

### Notes

CMFs, cone fundamentals, and chromaticity coordinates. The upper panel shows the spectrum locus
(continuous line) and selected wavelengths (yellow circles) plotted in the Stiles & Burch (1955)
2-deg *r,g* chromaticity space, and the projection of the 2-deg L- (red diamond), M- (green
circle) and S- (blue square) cone fundamentals of Stockman & Sharpe (2000). The lower left panel shows the spectrum
locus (continuous line) and selected wavelengths (filled circles) plotted in the Stiles &
Burch (1955) 2-deg RGB space, and the L- (red line), M- (green line) and S- (blue line) cone

vectors. The lower right panel shows a version of CMF space with the plane R + G + B = 1 shown in gray. The
projections of selected points on the spectrum locus onto this plane are shown by the yellow
circles, and the projections of the L-, M- and S-cone vectors are shown by the red diamond,
green circle, and blue square, respectively

### References

Stiles, W. S. (1955). Interim report to the Commission Internationale de l'Ã‰clairage Zurich, 1955, on the National Physical Laboratory's investigation of colour-matching (1955) with an appendix by W. S. Stiles & J. M. Burch. Optica Acta, 2, 168-181.

Stockman, A. (2004). Colorimetry. In T. G. Brown, K. Creath, H. Kogelnik, M. A. Kriss, J. Schmit & M. J. Weber (Eds.), *The Optics Encyclopedia: Basic Foundations and Practical Applications (Vol. 1, pp. 207-226).* Berlin: Wiley-VCH.

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.