The Colour Bilnd Leading the Blind

  • How we see colour
  • Modelling colour digitally
  • Modelling human colour perception
  • Demo
  • Trichromatic colour
  • Colour Blindness = Dichromacy
  • Monochromacy
dichromatic vision
  • Trichromat ~1million colours
  • Dichromat ~10k colours

Colour Spaces

RGB

Problems with RGB

  • Distance in RGB space is not perceptually uniform
  • Cannot represent all colours humans can see
HSV

Perceptually uniform colour spaces

a given numerical change corresponds to a similar perceived change in color
Munsell System
CIELAB
DEMO
  • Camera sampling from RGB
  • Chromatic Adaption
Bonus Content
RGB approximation of brightness
brightness = sqrt( .241 R2 + .691 G2 + .068 B2 )
Gradients