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 Post subject: Musings on RGB
PostPosted: Wed Sep 29, 2004 7:05 am 
Glow Ball
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Something that I've always wondered. Why is it RGB and not RYB? Aren't the primary colors red, yellow and blue? So, why don't computers use the primary colors as the base rather than mixing in the secondary color green? (orange and purple being the other two). Is there such a thing as thirdary (tercery) colors? What would they be? In psp, if I create a sixteen color graphic, I get these colors.

<center><img src="http://mtm2.com/~forum/images/palette16.gif" width="303" height="30"></center>

Why this particular sixteen and not a different other sixteen? And how did tri ever settle on the colors in it's <a href="http://mtm2.com/~forum/images/palettepsp5.gif">metalcr2</a> act <a href="http://mtm2.com/~forum/images/palettetraxx.gif">file</a> and how come those are different from any paint program that I've seen that creates a 256 color palette.

<center><img src="http://mtm2.com/~forum/images/palette256.gif" width="298" height="301"></center>

And if that isn't weird enough, why don't printers accept RGB even tho they're computer peripherals? I mean, cyan magenta yellow? Where does that come from? And that's the three in CMYK. What's up with the K? Does anybody know what color begins with the letter K? And who names these colors anyway. Now, I don't use named-colors in web pages, I use the #000000 color codes, but have you ever seen the names IE uses for web pages? I snagged two samples for reference sake [ <a href="http://mtm2.com/~forum/images/palettes_browser1.html">1</a> | <a href="http://mtm2.com/~forum/images/palettes_browser2.html">2</a> ] Holy mackeral! And how much does the guy make for giving the colors all those names and where can I get a job like that anyway. And while we're on the topic, where does the #000000 stuff come from and doesn't that system kind of cramp the 16 million color idea - seeing there's only six places, even tho they go up to F.... which I'm really glad we don't have to figure out how to spell in the metric system.

And yes, that's probably enough from me.... for now.


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 Post subject:
PostPosted: Wed Sep 29, 2004 4:04 pm 
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I'm not sure of the reason for the differences, but I suspect it has to do with the differences between mixing pigments (paint/ink) versus the mixing of different lengths of lightwaves (monitors/color TVs). I'm still searching for the differences.


THIS page has some explanations, but I haven't read through it yet. I will when I have time:

http://home.att.net/~RTRUSCIO/COLORSYS.htm

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 Post subject:
PostPosted: Wed Sep 29, 2004 5:48 pm 
Glow Ball
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That's not too bad a link, and it does explain the difference between monitor color and printer color - at least the theory behind them. But, most of all, what I get from it is that the theory of primary colors has changed since it was taught when I was in school. However. The explanations are weak and unconvincing. I'm not saying the content is not true - after all, there's amazing things being done with light nowadays - but to describe something as "secondary primary" is just nonsense. It's either primary or it's secondary. It can't be both. And I suppose this is the problem I'm having. It all seems rather arbitrary and random. For example, in the case of a monitor, that page says if we combine red and green we get yellow. But it's a computer for goodness sakes. We can program it to combine red and green to get pink if we want. There is no causal relationship between one color and another in a computer. Which is probably what prompted my ramble in the first place.

If we look at the page I linked to about named colors and pull a few values from it...

0,0,0 black
====
128,0,0 maroon
255,0,0 red

0,128,0 green
0,255,0 lime

0,0,128 navy
0,0,255 blue
====
128,128,128 gray
====
128,128,0 olive
255,255,0 yellow

128,0,128 purple
255,0,255 magenta

0,255,255 cyan
0,128,128 teal
====
255,255,255 white

... we can see how it's grounded in the theory att.net describes. Sort of. But that doesn't make it any less arbitrary. For example, number systems can be binary, octal, decimal, hex, etc. Each system is used for different purposes and neither invalidates the others. For colors, it appears to be the same way except that the motivation is lacking. Well, except for maybe hardware compatibility reasons, but that doesn't make the theory a physiological truth. Which leads us back to where we began. If psp generates a 256 color palette, why those colors? If tri made metalcr2, why those colors? If I want to create grass green, mud brown, or sky blue, how can I calculate the numerical rgb or cmy values for them before actually seeing them on the screen and using the color picker in psp to identify it. How can I create an optimized palette for a texture. How can I do anything except by trial and error. There has to be a way. I just don't see it in amongst this muddle of seemingly arbitrary chatter.

A parting thought.

Who ever invented internet code spelled the word <i>referrer</i> incorrectly and we've been living with it ever since. Nobody makes excuses for it, but nobody has attempted to fix it yet either. After all, everything still works.

In the case of colors, is it possible that the guy who invented the picture tube got his primaries mixed up and the world has been trying to rationalize it ever since? It's certainly the way it seems to me. And I've seen nothing to refute the idea either.


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 Post subject:
PostPosted: Wed Sep 29, 2004 8:30 pm 
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Luckily for you I am an expert in this subject. It all makes perfect sense once u know a couple things.

Printers, and paint, and little kids use SUBTRACTIVE color mixing.
Red (magenta), Yellow (amber), Blue(cyan).
CMYK
Cyan (blue), Magenta (red), Yellow (amber), blacK (B would be confused with blue)

Printers use black cause if u mix C+M+Y u just get very dark brown. To get a really nice black u have to have a seperate ink.

Ok, But i still havent explained what this SUBTRACTIVE thing is.
Subtractive means that you mix the colors by subtrating light.

If you have a white paper it reflects all the light. White light is all the colors mixed evenly. If you put down red paint it reflects more red wavelengths than the other stuff - there is still some of the other colors but it is even so it's just white. White+red=red. If you mix in more colors you get less light reflected. THats the subtractive part. If you want to have purple you mix in some blue. which take away less blue than any other color. So now you have more red and blue than other colors. You can keep subtracting colors until you have black.

So whats the alternative to subtractive - ADDITIVE.
Thats how you mix light. If you want red you just shoot out some red from the monitor. If you want green u shoot out green. If you want white you shoot out red, green, and blue evenly. In this case you start out with black and add photons of different wave lengths.

Additive color mixing can be acomplished with a printer. Simply print tiny dots of color and look at the picture from far away. This will be the equiv of a monitor. Some painters actually make artt hat up close looks like a bunch of dots but when you stand like a mile back it looks like a picture due to additive color mixing. Yes a guy actually made a huge picture ona mountain or somthing and u had to look at it from the next mountain.

here's an applet that lets u kinda see it in action
http://didaktik.physik.uni-wuerzburg.de ... color.html

Any questions?

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 Post subject:
PostPosted: Wed Sep 29, 2004 8:47 pm 
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here's some more good examples
http://users.pandora.be/educypedia/educ ... acolor.htm


Oh to answer your other questions.
Where does the #000000 stuff come from?
Well as you know a computer stores it;s numbers with 1's and 0's
imagine an odometer where each dial only had 2 sides instead of 10
you would see this:
0000 (0)
0001 (1)
0010 (2)
0011 (3)
0100 (4)
0101 (5)
0110 (6)
0111 (7)
1000 (8)
1001 (9)
1010 (12)
1011 (13)
1100 (14)
1101 (15)
1110 (16)
1111 (17)

Well HExadecimal would be like an odometer with 16 sides be dial:
0-9,A-F
So you would see
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
for the first 15 miles
well
a byte is 8 bits
which is 2^8 (256)
coincidently (not really)
it can be represented with the hexadecimal numbers: 00-FF
0-9,A-F
10-19,1A-1F
20-29,2A-2F
...
90-99,9A-9F
A0-A9,AA-AF
...
F0-F9,FA-FF
16^2=2^8
16*16=(2*2*2*2)*(2*2*2*2)

SO...
Remember that additive color mixing. well each pixle on the screen isnt one dot as every one has been telling you but it's three dots (if u look really close) each pixle has a red,green,and blue dot. Each dot can have 256 (FF) different amounts of brightness - from off to fully on. Well 256x256x256 = 16 million somthing. SO each pixle can have 16 million unique colors (not that you can tell the difference)
WELL
colors could be represented with three three digit numbers for the amount of ilumination of each color (RGB) like this:
#256000000
being fully red.
But that's kinda ugly (to programmers and nerds)
so we use
#FF0000

Thats about all there is to it.



As for optimized palettes... well i really have no idea how to 'optimize' a palette. You would have to make some sort of routine that figues out which 16 or 256 colors make the least error in your picture.
You might be able to find this kind of routine open source somplace.
Thats why i dont do it for people in c-pod - i make psp do it. THey are the color experts.

A tricky thing that fancy programs do is called ditering. Thats where stuff ends up kinda dotty. Thats cause the program is making another use of additive color mixing. By making tiny dots you can make it look like another color to the human eye+brain.

Umm THats about all i can think of. If u have any qestions post them here.

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 Post subject:
PostPosted: Wed Sep 29, 2004 9:05 pm 
Glow Ball
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Oh my.


:lol:


Yes, I have questions. But please give me a few days to recover first, lol.


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 Post subject:
PostPosted: Wed Sep 29, 2004 9:37 pm 
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...If you want to sum that up quickly...Bill gates made windows, thats why the colors are werid end of story :D

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 Post subject:
PostPosted: Wed Sep 29, 2004 10:52 pm 
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Quote:
Bill gates made windows, thats why the colors are werid end of story


Bill made an operating system. He didn't invent binary, hex-decimal systems, composite color TV's nor RGB monitors.....I'm afraid to say that this story remains open.

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 Post subject:
PostPosted: Wed Sep 29, 2004 11:04 pm 
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ZOtm_BigDOGGe wrote:
Quote:
Bill gates made windows, thats why the colors are werid end of story


Bill made an operating system. He didn't invent binary, hex-decimal systems, composite color TV's nor RGB monitors.....I'm afraid to say that this story remains open.

...I may be wrong there..But i sware he is to blame for bouncing the release date for halo 2 :x dern him and his windowish tactics

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 Post subject:
PostPosted: Thu Sep 30, 2004 7:14 am 
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Joined: Thu Sep 04, 2003 1:48 pm
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Apparently you haven't seen Microsoft Visual Studio .NET. Click "Color Change" or whatever and you have not one, but THREE tabs of colors!

You've got "WEB" colors, "SYSTEM" colors, and I forget the last one.

It has all those wierd color names and more!


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