Friday, June 7, 2013

Why color naming

Mid June 1993 I was strolling along the Duna river in Szentendre with Antal Nemcsics and Lucia Ronchi. We stopped, looking across the river, while Nemcsics was explaining his Dynamic Color theory. Then he turned around and with a broad sweep of his arm he referred to the cityscape stating "it has just been all repainted in its original colors; is it not beautiful how all these yellows from the local clays harmonize?" He then started calling out the names for the yellows and explained how the restoration was based on the sequence of the color names.

When I interjected that color names are arbitrary conventions between painters, and sequences in a perceptually uniform color space might be better, he countered that the color names were not arbitrary but based on solid psychophysics. He answered my question on how the 15 students typically recruited for psychophysical experiments could define something so complex as the names of colors, with the bold statement that for many years all his students had to contribute their data and his Coloroid system was based on the outcome of over 80,000 experiments. Wow, big data!

I had to turn around to the Duna river and take a deep breath. That instant in Szentendre remained deeply impressed in my memory, and I visualized the color name regions of varying volume in the Coloroid space.

A decade later, when I was working on the readability problem of colored text on a colored background, I first implemented an algorithm based on distances in CIELAB. While the solution worked from an engineering point of view, it was not entirely satisfying, because a fixed distance in the entire CIELAB space did not reflect the reality of readability for the various color combinations.

Szentendre came to mind and I decided to try out a different implementation based on lexical distances. Implementing the Coloroid system was not a piece of cake, because the calculations are numerically instable and not all the details of the space are published. Also, if the color names in the Coloroid atlas are adequate for urbanistic applications, some extensions are required to achieve a bullet-proof application for automatic document publishing.

Boundary color Coloroid luminance

I presented the result at the 2005 AIC meeting in Granada, but I must admit that not many people stopped by at my poster, although it resulted in a collaboration with Silvia Zuffi on the CIELAB based implementation.

Coloroid hue A = 20

Since the color naming solution was going into a product, a patent application was filed, but very reluctantly and with much hesitation. Indeed, color naming and color categorization were very controversial.

Suddenly, in the last few days everything has changed. We now know experimentally that at the quantum level time does not really exists as we perceive it. This new twist on entanglement is one of the tenets for Federico Faggin's new proposal for the concept of awareness. In one arm of the entanglement we have Kirsty L. Spalding, who after a decade of very difficult work studying the hippocampus of people exposed to the fallout of nuclear bomb tests was able to prove experimentally the physiological existence of a locus for categorization. In the other arm we have patent 8,456,694, which thanks to this entanglement is made rock solid.