Newsmaker: Bringing color to the color-blind

The world may be in living color, but not everyone sees it that way.

Peter Jones and longtime business partner Dennis Purcell, who met at Polaroid, over the years have developed technology for color meters for commercial photography and film, and invented an architectural model camera that Polaroid, once a leading player in the photography business, licensed and produced.

Now at Boston-based Tenebraex--where Jones is president and Purcell is senior scientist--the two have taken their color technology knowledge into both the dark night and the digital world of color-coded data.

Their refinement of the previously unsubstantiated Retinex theory of color vision, put forth by Polaroid founder Edwin Land, may both help soldiers carrying out nighttime missions and bring some relief to the 8 percent of American men and half-percent of American women who struggle daily with color blindness.

Jones, the photographer turned entrepreneur, gives his opinion on color blindness in a digital world driven by colorful data, and the stark reality of what color night vision, technology Tenebraex is pioneering, can do for the military.

Q: You've developed color night vision and software for the color-blind as well. How did you get interested in color technology?
Jones: Both Dennis and I used to work for Polaroid in years past, back when they were a big deal, and color was always of interest to us. Dennis actually invented a color meter for photographers that Polaroid licensed back in the early '80s. He came up with innovative ways for measuring the characteristics of light so you could come up with a set of filters that you could use on slide film, which was very intolerant of different kinds of light sources.

Dennis and I had invented a camera type that we had actually licensed to Polaroid and they put in production years ago. It was an architectural model camera. We've always had an interest in color, in color matters. Edwin Land (the founder of Polaroid) developed a theory of how your brain perceives color, which he called Retinex theory, that we always thought was correct.

If Edwin Land's theory wasn't right, you would not see color when you looked through our device.

What is the theory?
Jones: Retinex says that rather than measuring, what's first important to you is the name of the color, and being consistently independent of what color light is illuminating a scene. So if you're seeing a tiger at sunset or a tiger under a green forest canopy, you want it to still look orange even though the light that's hitting your eye may be a completely different color depending on what the illuminating light is like. And his Retinex theory said that your brain compared images of the three different channels--the red, green and blue senses in your retina--and from that, looking at the relative brightness, it figured out what the correct color name was and that's what you saw.

Depending on the brightness?
Jones: Well, by comparing the brightness. For instance, with your green senses in your retina, a piece of orange paper looks dark, while a piece of green paper looks bright. By comparing the two, your brain figures out what the correct color should be. That's why, for instance, if you take slide pictures under fluorescence, incandescent (light) or daylight, the pictures would be orange or green or blue or normal depending on the color of light. At the same time, to your eye, everything looks consistently the same color. Land's theory was about how colors look consistently the same pretty much irrespective of what color light is illuminating.

They stopped teaching his theory in school because he was just a businessman. We (Jones and Purcell) always thought he was correct. Four-plus years ago we figured, whatever the inspiration comes from, this conceptual framework might allow us to just figure out a way of making a practical four-color night vision system. And for our color night-vision system we figured out a way to make your brain see all of the colors while using only two channels, not three, which most people say you can't do.

You know, at conferences I'll say, "well, we're working with the Retinex theory" and, you know, people go, "Ha, ha, ha; he was just a businessman. He wasn't a real scientist." Well, he was one of the smartest people in the last century and we think his theory was right. And if his theory wasn't right, you would not see color when you looked through our device.

Can you explain that?
Jones: Most people think you need red, green and blue (RGB) or cyan, magenta and yellow (CMYK) in order to render all of the colors. But that's not true. You can do it with two dimensions. I don't know if you've ever seen a color diagram that has all the colors of the spectrum, but you can see all the colors by rendering it on a two-dimensional graph. What you need a third dimension for is so you can see, say, dark red versus light red or dark blue versus light red. The vertical access is only for brightness.

Are the ColorPath color night vision goggles and the EyePilot software for the color-blind born out of the same technology?
Jones: It's in the same researching way of thinking about the problem because then we said...You know, I don't know where this thought came from. But one way of describing a color-blind man, and most people who are color-blind are men, is that the output of their red and green channels are fused and they really only have a two-channel system. Well, I wondered if anything we learned from the ColorPath with a two-channel full-color system would allow us to help color-blind men see the full range of colors, to differentiate the full range of colors.

More Newsmakers

[NoVista]

Virtual colour

At one time, he was listed in the Guinness Book of World Records as the world's richest scientist. [borrowed from Wikipedia]

There's a good biography by McElheny, "Insisting on the Impossible".

When I was a budding television engineer, somebody told me about Land's two-colour experiments. That was published first, I believe in Scientific American, 1959 ...

Around the late 60s, the Japanese did some colour rendering experiments using black-and-white film projectors, and probably some exectronic switching, taking advantage of human persistence of vision.

I remembered from uni psychology class, some rotating disk with a pattern on it which at some rpm speed produced a colour effect. Aha, so I did an experiment in the workshop once with a B&W camera, greyscale chart, and experimental field switching breadboard. Although I didn't achieve a broad spectrum, there was some virtual colour perception. For me, and others. Curiously, one or two witnesses still saw nothing but B&W.