Mathematical relationship between the colour vision systems of trichromats and dichromats

Abstract

In § 1 and § 2 the experimental laws governing the colour vision trichromats and dichromats are briefly discussed and the eye is compared to a system of three or two photo-cells. In § 3 starting from the Grass-mann laws and the fact that a colour match made by a trichromat is also admitted as correct by the dichromat, two general laws are proved: a) the dichromatic distribution curves are linear functions of the trichromatic distribution curves. b) when a suitable linear transformation is applied, these distribution curves (spectral sensitivities of the photo-cells) take the form of scheme (6). In § 4 the functions of this scheme are determined numerically from Pitt's experimental data on dichromats. In § 5 the results are discussed in connection with the Young-Helmholtz-König theory of colour vision and with the colour adaptation experiments made by Wright.