4. Conclusion

Color is therefore a perception that can be expressed using a nomenclature, whether rationalized analogically or digitally. Three essential parameters are involved: the hue, luminosity and saturation of the stimulus.

To digitize colors, equalization functions were experimentally derived using a standard population. A graphical representation of these gave rise to the RGB space. Negative values show that a combination of the three primaries cannot render all colors. Consequently, the XYZ space, based on imaginary primaries, was defined to overcome this limitation. As it is perceptually non-uniform, the CIE applied a non-linear transformation. This gives rise to the L*a*b space, which mimics as closely as possible the eye's logarithmic response to luminance. This makes it possible to simulate trichromatic values, taking into account illumination, sample reflection...