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Tristimulus values

Tristimulus values X, Y and Z are the amounts of the three primary colors (red, green and blue) of the visible spectrum of light from 380-780 nm that specify a color stimulus. They will be derived from the following equations:

Legend:

Legend
  • X, Y, Z: tristimulus values
  • h: Normalisation factor such that Y = 100 for a sample that reflects 100% at all wavelengths. Thus
  • Sl: represents reflectance values of an energy spectrum measured with a UV/VIS spectrometer for surround of wave l in given white light - from illuminant.
  • Pl: represents the relative spectral energy distributions of the illuminant
  • xl, yl, zl: standard observer functions