How many spectral basis functions do red – green dichromats need to discriminate surface colours under different lights?
” Perception 32 ECVP Abstract Supplement How many spectral basis functions do red – green dichromats need to discriminate surface colours under different lights? E K Oxtoby, D H Foster, R C Baraas For observers with normal colour vision, reflectance spectra can be adequately represented by linear models with at least five basis functions in tasks requiring the discrimination of Mondrian-like coloured patterns of Munsell papers. This number of basis functions is needed whether the patterns are presented under the same or different illuminants (Oxtoby et al, 2002 Perception 31 Supplement, 66), which may be important in understanding surface-colour perception. Fewer basis functions should be needed, however, for dichromats, who have just two distinct cone classes, but it is unclear whether the number of basis functions would be reduced still further across an illuminant change. Accordingly, red – green dichromatic observers were presented with computer simulations of pairs of Mondrian-lik
