AuthorTopic: Hue/saturation adj. unsensitive palette.  (Read 4162 times)

Offline Gas 13

  • 0001
  • *
  • Posts: 82
  • Karma: +0/-0
  • Osmi the Octopus
    • View Profile
    • Pixelart and Photoshop tutorials

Hue/saturation adj. unsensitive palette.

on: November 09, 2006, 01:04:56 am
Are you familiar with a palette that will work fine for any hue saturation adjustment? I mean you pixelate something and by adjusting hue/saturation you can get that in all colors of rainbow and it still will look fine. Is it possible?

I suppose no since if you add some cyan for highlights to blue it will not work as a highlight if you adjust hue... But who knows, maybe there's a way... Using gradient from some to color to white doesn't work also.

But it seems to me some developers were using this trick...

Let me know what you know please.

Offline Indigo

  • Administrator
  • 0011
  • *
  • Posts: 946
  • Karma: +0/-0
  • Artist, Indie Game Dev
    • DanFessler
    • DanFessler
    • http://pixeljoint.com/p/849.htm
    • DanFessler
    • DanFessler
    • View Profile
    • Portfolio

Re: Hue/saturation adj. unsensitive palette.

Reply #1 on: November 09, 2006, 01:50:21 am
you can do this perfectly as long as the whole sprite is of the same hue. (different values and saturation is fine)  a monotone image basically.  As soon as you have some hue shifting in your image and *then* you decide the use the hue slider, alot of cases it will show up like a mess.

Offline AlexHW

  • 0100
  • ***
  • Posts: 1037
  • Karma: +0/-0
    • View Profile
    • AlexHW

Re: Hue/saturation adj. unsensitive palette.

Reply #2 on: November 09, 2006, 01:50:47 am
first off.. you can change the color, but you can't change the value..
when you adjust the hue in a program, it changes the values.. best bet is doing it manually, or developing some custom algorithm for chanign hues without changing their value..
next, it depends upon what it is that is being adjusted, some things are just more difficult to manage.

edit: what indigo suggests would work, and is what most game developers do(construct images in greyscale, and then tint them with code).. you could also use differeny grey gradients for different pieces, so as to be able to adjust the palette accordingly as a whole, i think..
« Last Edit: November 09, 2006, 01:53:57 am by Alex Hanson-White »

Offline Indigo

  • Administrator
  • 0011
  • *
  • Posts: 946
  • Karma: +0/-0
  • Artist, Indie Game Dev
    • DanFessler
    • DanFessler
    • http://pixeljoint.com/p/849.htm
    • DanFessler
    • DanFessler
    • View Profile
    • Portfolio

Re: Hue/saturation adj. unsensitive palette.

Reply #3 on: November 09, 2006, 01:53:51 am
hues have a natural value that the computer doesn't account for.  Yellow for example, on a value scale of 1-8, at 100% saturation, would be about a 2 A blue at 100% saturation would be about a 4. Despite this, both colours are only known to the computer as full brightness, or rgb255.  Like Alex said.  Unless you can write a program to distinguish natural value, this cannot be done how your describing it.

Offline goat

  • 0010
  • *
  • Posts: 230
  • Karma: +0/-0
  • bl33t
    • View Profile

Re: Hue/saturation adj. unsensitive palette.

Reply #4 on: November 09, 2006, 02:02:22 pm
Some hardware accounted for the innate intensity of different hues; the SNES I believe used that principle to make some pretty cool looking blends and fades. 

But yeah, if I recall correctly, if the relative intensity of pure white is 100% on an RGB display, then green accounts for about 20%, red is a little over 70%, and blue usually sits below 10%.  In an additive color system these intensities appear to just add onto each other, which is why yellow is so freaking intense (it approaches 100%) and why FF00FF resembles a hot eyebleeding pink rather than an equal blend of red and blue, which it is; the intensity of the red simply dominates the blue. 

As to why Yellow appears only about 2x brighter than blue like Indigo said rather than the 8-9x I described above, those numbers just describe the quantitave intensity. The actual visual intensity depends on your gamma settings and the sensitivity of your eyes, since the relationship between color attribute values and their visual intensity is quite nonlinear and subject to people's/an individual's sensitivity (green appears WAY more intense than blue because iirc the human eye is generally more sensitive to it)

But yeah, actually Pep and I were just rambling on about similar color phenomena the other night... it might be a good idea for all of us to pool our knowledge on the topic into something other people can use :p
« Last Edit: November 09, 2006, 02:05:43 pm by goat »
typing ewith fdace

Offline Lawrence

  • 0010
  • *
  • Posts: 200
  • Karma: +0/-0
    • View Profile

Re: Hue/saturation adj. unsensitive palette.

Reply #5 on: November 09, 2006, 02:27:10 pm
If I want help checking the luminance of my colours, I just quickly hit crtrl+G in mtPaint to see the values in greyscale and then quickly undo. As previously said, if you want control over luminance you have to do it manually in a way like this, but the strange thing is, so many programs can sort a palette by luminace, can convert to greyscale giving you the luminance, but cannot incorporate luminance any more than that which is annoying.

Offline Peppermint Pig

  • 0010
  • *
  • Posts: 495
  • Karma: +0/-0
    • View Profile

Re: Hue/saturation adj. unsensitive palette.

Reply #6 on: November 09, 2006, 05:13:42 pm
One solution is to create art without consideration of hue shifting or atmosphere, then apply a highlight blend and an atmosphere blend to your work. That way you can have a master sprite, which is as unbiased as possible.

Offline Gas 13

  • 0001
  • *
  • Posts: 82
  • Karma: +0/-0
  • Osmi the Octopus
    • View Profile
    • Pixelart and Photoshop tutorials

Re: Hue/saturation adj. unsensitive palette.

Reply #7 on: November 10, 2006, 10:00:46 am
Thanks for sharing your knowledge, guys. I have turned the sprite to greyscale and adjusted contrast and now it works fine in my opinion. At least I can get not so weird looking gems of different colors out of it playing with hue and saturation.

This time it's all about several gems to get an economy of several bytes for Nokia S40 devices, but I would really love to know what are that highlight and an atmosphere blends, Pep? Do you mean some kind of layers with opacity? Could you give any example?