Talk:RGB color model
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Subject: Psychological Primary Colors
The "red" and "green" that the R and G were named after in RGB are actually more yellow than pure red and pure green, defining such as being neutral on the blue-yellow scale, which are 2 of the 6 psychological primary colors. The psychological primary colors and their RGB coordinates are:
Red = 255 0 128
- I just opened up an xterm with that color and it looks sort of pink. If I just use 255, 0, 0, it looks red. Michael Hardy 02:21, 18 Feb 2004 (UTC)
Yellow = 255 255 0 Green = 0 255 128 Blue = 0 0 255 Black = 0 0 0 White = 255 255 255
Of course, gray is 128 128 128; note that it is a mixture of any 2 colors that are complements, such as black and white, blue and yellow, and red and green. How about the secondary colors
Red + Yellow = Orange (255 83 0) Yellow + Green = Lime (83 255 0)
- This is ridiculous: orange and lime are disambiguation pages, not pages about colors!! Michael Hardy 02:24, 18 Feb 2004 (UTC)
Green + Blue = Sea Blue (0 172 255) Blue + Red = Purple (172 0 255)
Anything + Black = half the distances between the coordinates and 0 Anything + White = half the distances between the coordinates and 255
See also the messages at Color, Red and Primary Color that also have to do with psychological primary colors.
- Why link to Primary Color with a capital "C" when no such page exists, and you could link to primary color with an appropriately lower-case "c", which does exist? (The capitalized page now exists as a redirect page; I just created it.) Please check your links to see if they're working right!! Michael Hardy 02:28, 18 Feb 2004 (UTC)
History of RGB color model - RCA, Edwin Land ...
Would it be possible to include some history of the use of the RGB color scheme - including for example, the RCA standards for color television that were adopted in 1953, Edwin Land's use of an RGB scheme for the Land / Polaroid camera and the introduction - and subsequent adoption by W3C in HTML 3.2 - of color="#rrggbb" as the Internet standard for the presentation of color.
I would also like to offer a link that perhaps might be included in the RGB color model, namely http://www.peace-cubes.net, the home of the Virtual Light and Colour Cubes - defined as virtual entities with dimensions of red, green and blue, in which the color at any point is the sum of the red, green and blue coordinates, where color="#rrggbb" is understood as an arithmetic expression in a three-dimensional mathematics of light and color.
<p>
Yhe Virtual Light and Colour Cubes were dedicated as Peace Cubes at the United Nations Peace Bell on March 20, 1997 - see http://habitat.igc.org/peace-cubes/dedicate.htm - and have served as icons for the transition to a digital knowledge-based universe in which we can see the world in transformed and transformative ways, and as a reminder of the existence of one light in all of creation - in the digital world as well as in material realms.
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Robert Pollard
Information Ecologist & Digital Artist
ecology2001@mindspring.com
Information Habitat: Where Information Lives - Home of the Virtual Light & Colour Cubes
http://habitat.igc.org/
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- This looks like a semi advert. I'm at loss weather to delete it or keep it Kim Bruning 16:25, 9 Apr 2004 (UTC)
Article has a slight POV slant
...in favor of 8 bits per channel. What about methods that represent RGB as floating point proportions (like OpenGL does, IIRC) or that represent RGB in *more* than 8 bits per channel (I'd imagine specialised applications or simply photo editing where that'd be important).
Hmm. Kim Bruning 16:20, 9 Apr 2004 (UTC)
- given that (at normal viewing distance and resolution) only four bits are actually needed for green, ~3.5 for red, and 2 for blue, suggesting that more bits bit be useful could be misleading. 8 bits per channel is a convenience (as it means some image processing calculations can be done more simply), and the same is true for using floating-point values, but all those extra bits are a bit of an indulgence :-) mfc
Who cares about the human visual system?
- Extra bits are useful for more accurate measurements for scientific purposes.
- Natural lighting can have a massive dynamic range.
- Even if the human eye can only grab a subset of that range, doesn't mean there might not be a reason to record light levels across the entire range (and then later be able to pick out cross-sections from that range to view different parts of our recording).
- Have you ever noticed how many rendered images look so flat? This is especially true of "outside pictures".It'd help if those rays actually were traced at a higher color-depth. You could then select your viewing pane coordinates in color space* as well as euclidian space. This would be akin to setting the light sensitivity (ISO value && partially also diafragma) on your virtual camera. (Hmm, I'd actually have to look up to see if some renderers don't already do that.)
- When editing in the colorspace of a photo, sometimes I just run out of bits! Arrrgh, bother, time to retake that photo. If the camera had just been able to record at just a little more colordepth , I could have managed. (This is related to my hard-disk always having juust too little space for those images to fit too. :-P )
- Fortunately, some cameras already have a raw output format at 16 bits per channel. :-) Unfortunately these are almost always proprietary. :-(
Hope this gives a bit of an idea why a larger color-space might be useful. :-) Kim Bruning 18:55, 9 Apr 2004 (UTC)
* in a way that would actually be meaningful.