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My ultimate hope is that this will allow us to store and display color data as Fourier series.

Right now we only represent colour as combinations of red, green, and blue, when a colour signal itself is really a combination of multiple "spectral" (pure) colour waves, which can be anything in the rainbow.

Individually controllable microLEDs would change this entirely. We could visualize any color at will by combining them.

It's depressing that nowadays we have this technology yet video compression means I haven't seen a smooth gradient in a movie or TV show in years.

3 comments

What would be the purpose of this?

The human eye can't distinguish light spectra producing identical tristimulus values. Thus for display purposes [1], color can be perfectly represented by 3 scalars.

[1] lighting is where the exact spectrum matters, c.f. color rendering index

Color data has three components for the simple reason that the human eye has three different color receptors. You can change the coordinate system of that color space, but three components will remain the most parsimonious representation.

I started working with a hyperspectral imager a while back and the idea of storing image data in 3 wide bands seems so odd to me now. Just the fact that my HSI captures 25 distinct 4nm bands inside a single 100nm band of what we are used to with a 3-band image is awesome.

Sorry, I get excited every time I work with hyperspec stuff now and love talking about it to anyone that will listen.

Hyperspectral imaging has its applications. A hyperspectral display on the other hand makes no sense (unless your target audience consists of mantis shrimps).

> I get excited every time I work with hyperspec stuff now and love talking about it to anyone that will listen.

Color is widely taught down to K-2, but content and outcomes are poor. So I was exploring how one might better teach color, with an emphasis on spectra. Using multispectral/hyperspectral images of everyday life, objects, and art, seemed an obvious opportunity. Mousing over images like[1] for example, showing spectra vaguely like[2]. But I found very few (non-terrain) images that were explicitly open-licensed for reuse. It seemed the usual issue - there's so much nice stuff out there, living only on people's disks, for perceived lack of interest in it. So FWIW, I note I would have been delighted to find someone had made such images available. Happy to chat about the area.

[1] http://www.ok.sc.e.titech.ac.jp/res/MSI/MSIdata31.html [2] https://imgur.com/a/teaching-color-using-spectra-zOtxQwe

With two wavelength-tunable LEDs you should be able to cover the entire CIE colorspace.

That's because the points on outer edge of CIE are pure wavelengths and you can get to any point inside by interpolating between two of them.

How do you make white?

E.g. mix 480nm cyan and 590nm orange.

Would this be practical? Or would it be similar to how printers have separate black ink, which is theoretically unnecessary?

By mixing two complementary colors.