Color: From Hex codes to Eyeballs • Hacker News Board

Re: Color: From Hex codes to Eyeballs

#51

Post by jacobolus » Tue, Apr 10, 2018, 5:33 PM UTC

thanatropism wrote: post #43

pluma wrote: post #38

Earlier quoted context omitted.

As a "colorblind" person, this is a bit frustrating so bear with me. Few people are literally "colorblind". You don't have one cone cell of each type, you have loads of them. Colorblind people generally have fewer of them (or some of them are shifted) but usually only for one type (usually red/green). The "red" and "green" cones overlap quite a lot[1] and they also overlap with the rods. This means that even if you l…

> Physically isolating certain wavelengths produces a "pure green" light. What, can we get an wavelength-energy distribution that looks like a Dirac delta? There are discontinuities in physics but you kinda need to be careful to see if what you think is a discontinuity is one.

You can use a laser. https://en.wikipedia.org/wiki/Coherence_(physics)#Temporal_c...

Re: Color: From Hex codes to Eyeballs

#52

Post by zokier » Tue, Apr 10, 2018, 7:54 PM UTC

yuchi wrote: post #39

zokier wrote: post #30

One interesting facet of all this is that afaik most of our hyper-realistic "physically based rendering" 3D renderers are still based on these color models instead of modeling the light spectrally. I imagine that somewhere in near future that will change as we start reaching the limits of the color models. It is actually interesting how well simple RGB has served in practice when it is fairly simple to imagine scenes…

See https://news.ycombinator.com/item?id=16799578

I did some googling around and seems like spectral rendering is escaping the research labs; Weta is reported to be using spectral rendering and Wikipedia lists several renderers in the "Spectral rendering" page:

> For example, Arion,[1] FluidRay[2] Indigo Renderer,[3] LuxRender,[4] mental ray,[5] Mitsuba,[6] Octane Render,[7] Spectral Studio,[8] Thea Render[9] and Ocean[10] describe themselves as spectral renderers.

https://en.wikipedia.org/wiki/Spectral_rendering

Of those, LuxRender is of special interest considering that it is FOSS and as such freely available.

Re: Color: From Hex codes to Eyeballs

#53

Post by mark-r » Tue, Apr 10, 2018, 9:01 PM UTC

mclehman wrote: post #49

mark-r wrote: post #45

Earlier quoted context omitted.

I apologize for my ignorance of the specifics of color blindness, I don't suffer from it myself. I've just been so fascinated by the concept of these glasses that I can't help sharing.

There is also a very large range of responses to the EnChroma glasses. I've seen or heard about plenty of intense reactions to them, but my personal experience has not reflected that. My brother-in-law and I are both colorblind (mine is not as severe as his) and he bought a pair a few years ago. He enjoys the difference but not enough to wear them consistently, and they had a barely perceptible effect on my own visio…

I always assumed the large range of responses was due to a large variation in the way color blindness manifests. Also perhaps on how your neurons have adapted to the condition; I wonder if age plays a role?

Re: Color: From Hex codes to Eyeballs

#54

Post by pluma » Thu, Apr 12, 2018, 1:00 PM UTC

jacobolus wrote: post #50

pluma wrote: post #38

Earlier quoted context omitted.

As a "colorblind" person, this is a bit frustrating so bear with me. Few people are literally "colorblind". You don't have one cone cell of each type, you have loads of them. Colorblind people generally have fewer of them (or some of them are shifted) but usually only for one type (usually red/green). The "red" and "green" cones overlap quite a lot[1] and they also overlap with the rods. This means that even if you l…

The genes for L and M cones are on the X chromosome and there are some variants for each type, or sometimes one is missing. This mostly affects men, since they have only one X chromosome, so if the gene for e.g. the L cones is missing then they end up as dichromate or if they get two variants which overlap too much there isn't much differential signal. A small number of women end up as tetrachromats because they have…

FWIW from the few studies about human tetrachromacy that I've heard of it seems that the women do in fact just see some similar-looking colors as more obviously distinct.

AIUI In order to see any "new" colors (i.e. outside the "visible" spectrum) they'd need to be more sensitive to UV or IR light (which in addition to being able to perceive those in isolation would presumably also mean being able to perceive those in combination, which indeed would drastically extend the numbers of colors).

Re: Color: From Hex codes to Eyeballs

#55

Post by thanatropism » Thu, Apr 12, 2018, 3:44 PM UTC

jacobolus wrote: post #51

thanatropism wrote: post #43

Earlier quoted context omitted.

> Physically isolating certain wavelengths produces a "pure green" light. What, can we get an wavelength-energy distribution that looks like a Dirac delta? There are discontinuities in physics but you kinda need to be careful to see if what you think is a discontinuity is one.

You can use a laser. https://en.wikipedia.org/wiki/Coherence_(physics)#Temporal_c...

What this is saying is that a perfect sinusoid has a single frequency?

Of course. Sorry, I'm stupid. Born like that.