Uniform-Colour Space for Colour Displays

Abstract

Recently, a uniform-scale chromaticity diagram has been defined for a 2° visual field in agreement with MacAdam ellipses by an angular hypothesis around two angular variables whose centres are the deuteranopic and tritanopic confusion points, respectively. This hypothesis is applied to the subspace reproduceable by trichromatic displays. Nezv chromaticity co-ordinates obtained by two logarithmic transformations constitute cartesian co-ordinates with uniform scale on the chromatic palettes at constant luminance. The shape of these palettes can be very regular (rectangle In a wide range of luminances) by using two angular variables whose centres are two points lying on the alychne (i.e. the line on the chromaticity diagram corresponding to zero-luminance stimuli), dependent on the chromatic- ities of the red, green and blue (RGB) primary colours and close to the tritanopic and deuteranopic confusion points. Such a choice of angular centres could create some scale distortion in the region of the blue hues that may vanish for a suitable set of RGB primaries.

Notes

Paper presented at the RPS Symposium “Images in Colour”, 10-12 April 1994, Cambridge.