housemate is colorblind
Sep. 8th, 2005 03:35 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
guslI just found out that my new housemate, Edgar, is colorblind.
I've had tonedeaf housemates before, but never a colorblind one.
I want to find the right shades of red/green that he can't distinguish... he says that he can always detect boundaries, but I suspect he's wrong. On his side is the evidence that pictures in colorblindness tests are boundary free: they make the number in a swarm of dots...
My theory is that colorblindness can be modelled by a projection from a 3-dimensional into a 2-dimensional color space R x G x B -> RG x B, where the red and green dimensions collapse into one red-green dimension. (oh, pardon me, I'm being 3Dcolor-centric: the real color spectrum is (potentially) infinite-dimensional)
In practice, I think colorblind people often distinguish green from red by darkness levels... but this obviously fails a lot.
I think they make the test this way (boundary-free, dots being different shades of red and green) because different individuals have different projections. So for the test to catch most red/green colorblind people, it needs to be this way.... although they could also make a test with tiles instead of dots.
Also, note that the thickness of the numbers is 1 or 2 circles. If there were many more, then some colorblind people (those whose projection is far from the average projection) might notice a statistically-significant difference in darkness, and therefore see the numbers.
Oh, Henry Sturman has convinced me that many colorblind people are actually differently-color-visioned.
(Pardon my inconsistent UK-US spelling.)
I've had tonedeaf housemates before, but never a colorblind one.
I want to find the right shades of red/green that he can't distinguish... he says that he can always detect boundaries, but I suspect he's wrong. On his side is the evidence that pictures in colorblindness tests are boundary free: they make the number in a swarm of dots...
My theory is that colorblindness can be modelled by a projection from a 3-dimensional into a 2-dimensional color space R x G x B -> RG x B, where the red and green dimensions collapse into one red-green dimension. (oh, pardon me, I'm being 3Dcolor-centric: the real color spectrum is (potentially) infinite-dimensional)
In practice, I think colorblind people often distinguish green from red by darkness levels... but this obviously fails a lot.
I think they make the test this way (boundary-free, dots being different shades of red and green) because different individuals have different projections. So for the test to catch most red/green colorblind people, it needs to be this way.... although they could also make a test with tiles instead of dots.
Also, note that the thickness of the numbers is 1 or 2 circles. If there were many more, then some colorblind people (those whose projection is far from the average projection) might notice a statistically-significant difference in darkness, and therefore see the numbers.
Oh, Henry Sturman has convinced me that many colorblind people are actually differently-color-visioned.
(Pardon my inconsistent UK-US spelling.)