4 ms·

Not an expert but I'll drop my 2c Most of my career was somehow related to graphics programming and I always thought it's bit weird that most quantization algo

by zeroq 11mo ago

Not an expert but I'll drop my 2c Most of my career was somehow related to graphics programming and I always thought it's bit weird that most quantization algorithms were operating in RGB model despite the fact that it was designed for hardware, not so for faithful color manipulation. The easiest way to see that is to imagine a gradient between two colors and trying to make it in RGB. It doesn't seem right most of the time. If so, then why would we consider distance in 3D space between two colors as faithful representation of their likeness? Well, lo and behold, it's 2025 and everyone finally accepting LAB as the new standard. :)

subb 11mo ago
Except color is a construction of your eye-brain derived from stimuli, surround, memories, etc. It's definitely not something you can plug into a three-value model. Those are good stimuli encoding space, however. The distinction between brain-color and physical-color is what screws everyone up.
- zeroq 11mo ago
  fun fact: there's a guy with similar background to mine, with similar dedication to color, yet way more productive and he came out with this incredible piece of art: rebelle app As with most recent technological breakthroughs it uses math from 1931 paper to magically blend colors in ways that seems so realistic it's almost uncanny.
- dahart 11mo ago
  > It's definitely not something you can plug into a three-value model. What do you mean? And what is screwed up? We use 3 dimensions because most of us are trichromats, and because (un-coincidentally) most digital display devices have 3 primaries. The three-value models definitely are sufficient for many color tasks & goals. Three-value models work so well that outside of science and graphics research it’s hard to find good reasons to need more, especially for art & design work. It’d be more interesting to identify cases where a 3d color model or color space doesn’t work… what cases are you thinking of? 3D cone response is neither physical (spectral) color nor perceptual (“brain”) color, and it lands much closer to the physically-based side of things, but completely physically justifies using 3D models without needing to understand the brain or perception, does it not?
  - IgorPartola 11mo ago
    I had experimented with some photo printing services and came across one professional level service that offered pigment inkjet printing (vs much more common dye inkjet printing). Their printers had 12 colors of ink vs the traditional 4. I did some test photos and visually they looked stunning.
    - wongarsu 11mo ago
      "You only need three colors" is a bit of a cheat, because it doesn't really work out in reality. You can use three colors to get a good color gamut (as your screen is doing right now), but to represent close to every color we can see you would need to choose a red and blue close to the edge of what we can perceive, which would make it very dim. And because human vision is weird you would need some negative red as well, which doesn't really exist. Printing instead uses colors that are in the range we can perceive well, and whenever you want a color that is beyond what a combination of the chosen CMYK tones can represent you just add more colors to widen your gamut. Also printed media arguably prints more information than just color (e.g. "metal" colors with different reflectivity, or "neon" colors that convert UV to visible light to appear unnaturally bright)
      - IgorPartola 11mo ago
        Which is interesting because I am printing digital photos which I edit on an RGB screen.
        mceachen 11mo ago
        I paid for college in part by doing digital prepress. We had CMYK and 8 and 12 color separations. CMYK always has a dramatic color shift from any on-screen colorspace. Vivid green is really hard to get. Neons are (kinda obviously) impossible. And, hilariously/ironically (given how prevalent they are), all manor of skin tones are tough too. Photoshop and Illustrator let you work in CMYK, and is directionally correct. Ask your printer if they accept those natively.
    - 11mo ago

by zeroq 11mo ago

subb 11mo ago

Except color is a construction of your eye-brain derived from stimuli, surround, memories, etc. It's definitely not something you can plug into a three-value model. Those are good stimuli encoding space, however. The distinction between brain-color and physical-color is what screws everyone up.

zeroq 11mo ago
fun fact: there's a guy with similar background to mine, with similar dedication to color, yet way more productive and he came out with this incredible piece of art: rebelle app As with most recent technological breakthroughs it uses math from 1931 paper to magically blend colors in ways that seems so realistic it's almost uncanny.
dahart 11mo ago
> It's definitely not something you can plug into a three-value model. What do you mean? And what is screwed up? We use 3 dimensions because most of us are trichromats, and because (un-coincidentally) most digital display devices have 3 primaries. The three-value models definitely are sufficient for many color tasks & goals. Three-value models work so well that outside of science and graphics research it’s hard to find good reasons to need more, especially for art & design work. It’d be more interesting to identify cases where a 3d color model or color space doesn’t work… what cases are you thinking of? 3D cone response is neither physical (spectral) color nor perceptual (“brain”) color, and it lands much closer to the physically-based side of things, but completely physically justifies using 3D models without needing to understand the brain or perception, does it not?
- IgorPartola 11mo ago
  I had experimented with some photo printing services and came across one professional level service that offered pigment inkjet printing (vs much more common dye inkjet printing). Their printers had 12 colors of ink vs the traditional 4. I did some test photos and visually they looked stunning.
  - wongarsu 11mo ago
    "You only need three colors" is a bit of a cheat, because it doesn't really work out in reality. You can use three colors to get a good color gamut (as your screen is doing right now), but to represent close to every color we can see you would need to choose a red and blue close to the edge of what we can perceive, which would make it very dim. And because human vision is weird you would need some negative red as well, which doesn't really exist. Printing instead uses colors that are in the range we can perceive well, and whenever you want a color that is beyond what a combination of the chosen CMYK tones can represent you just add more colors to widen your gamut. Also printed media arguably prints more information than just color (e.g. "metal" colors with different reflectivity, or "neon" colors that convert UV to visible light to appear unnaturally bright)
    - IgorPartola 11mo ago
      Which is interesting because I am printing digital photos which I edit on an RGB screen.
      - mceachen 11mo ago
        I paid for college in part by doing digital prepress. We had CMYK and 8 and 12 color separations. CMYK always has a dramatic color shift from any on-screen colorspace. Vivid green is really hard to get. Neons are (kinda obviously) impossible. And, hilariously/ironically (given how prevalent they are), all manor of skin tones are tough too. Photoshop and Illustrator let you work in CMYK, and is directionally correct. Ask your printer if they accept those natively.
  - 11mo ago