Whiteness metric for light sources of arbitrary color temperatures: proposal and application to light-emitting-diodes.

We study the quantification of whiteness perception under illumination from various light sources. We discuss an existing metric for sources with high correlated color temperature (CCT), CIE whiteness, and propose a procedure to adapt it to sources of any CCT. We illustrate our approach by comparing the ability of different warm-white sources to render whiteness. We show that a careful engineering of the spectrum -facilitated by the flexibility of light-emitting diode sources - is essential to render whiteness.