Hughes: Introducing the ColorHug open source colorimeter [LWN.net]

Hughes: Introducing the ColorHug open source colorimeter

Posted Nov 15, 2011 0:18 UTC (Tue) by nix (subscriber, #2304)
In reply to: Hughes: Introducing the ColorHug open source colorimeter by Wol
Parent article: Hughes: Introducing the ColorHug open source colorimeter

This is, of course, an example of *consistent* colour perception. The frequency mix of the light reflected from the banana has changed, but the *colour* is the same, because 'colour' is a thing entirely situated within the brain, and is corrected to a large degree for lighting conditions, shading, surface texture and much else. (Nothing we can build can do such a good job, let alone do it in realtime with noisy, constantly jittering input from input sensors laid out partly at random.)

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stochastic sensor placement

Posted Nov 15, 2011 14:30 UTC (Tue) by tialaramex (subscriber, #21167) [Link]

The "input sensors laid out partly at random" is actually a clever trick, which we do in fact use in things we build although not cameras so far as I know. The sensors are in fact arrayed stochastically, which inherently avoids artefacts like aliasing.

Suppose you're looking at, for example a distant checkerboard pattern. If you use a perfect rectangular grid of sensors at certain distances, you will "see" patterns that don't really exist because of the regularity of your sampling. If you instead "randomly" place the sensors according to a rule that limits their proximity you completely avoid this problem.

Pixar's Photorealistic Renderman (and presumably many other modern 3D rendering systems) likewise uses multiple stochastically chosen sample origin points for each pixel, with the same result - no aliasing.