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Representation of colors

  1. Jul 22, 2015 #1
    How many dimensions are necessary for repsent ALL colors? 3, 4, more!?

    What are the better ways for represent all colors inside 2D plane and 3D space.

    I already tried so much combination, but, a think that never it's 100% good.
     

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  3. Jul 22, 2015 #2
    I think all the perceived colours, every hue and every saturation, can be represented in two dimensions on the Colour Triangle (yet another Maxwell discovery). It is the basis of colour TV.
     
  4. Jul 22, 2015 #3

    HallsofIvy

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    Because the human eye has three different kinds of color receptors, specifically sensitive to light in the frequency ranges of red, green, and blue, we perceive light as a three dimensional property. Some color models directly use "RGB", representing a cube with intensity of red along one edge, intensity of blue along the other, and intensity of green along the third. There is also the "hue, saturation, and intensity" representation, first used in computer monitors by, I think, Tektronix, which represents colors on a double pointed cone with "hue" around the circle, intensity outward from the axis, and saturation along the axis. It is a double pointed cone because all colors become "black" as saturation goes to 0 and "white" as saturation goes to 100%.
     
    Last edited: Jul 31, 2015
  5. Jul 22, 2015 #4
    Unsure why a 2-dimensional diagram such as the colour triangle (which has RGB at its corners and white in the middle) cannot represent all perceived colours?
     
  6. Jul 22, 2015 #5

    HallsofIvy

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    You say "white n the middle" so I think you are having the intensity (also called "brightness") increasing toward the center. So where is black?
     
  7. Jul 22, 2015 #6
    Yes, I see your point. TV uses a separate luminance (Y) signal, so the colour triangle specifies only hue and saturation.
     
  8. Jul 22, 2015 #7
    But and about the CYMB system!? Is a pseudo 4D system!? Is, actually, a 3D system or not!?
     
  9. Jul 23, 2015 #8

    HallsofIvy

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    If we are creating colors by combining lights of different colors ("additive combination" as when we are shining light on our monitor screen) then our "basis" is Red, Blue, Green because, as I said, our eyes have optic nerves that are particularly sensitive to those three colors. If, instead, we are creating colors by shining white light through different filters (so that we are "subtracting" light as when we are putting ink on a paper) then our "basis" is the complementary colors Cyan (between green and blue), Magenta (between red and blue), and yellow (between red and green). Black isn't really necessary. It is added to the colored inks, first because the great majority of printing is NOT in color and just using black ink is cheaper and second because when used with colored inks in color pictures, it makes the contrast with the white paper better.
     
  10. Jul 23, 2015 #9
    Exist some program (interactive program, preferably) for vizualize the combinations between colors in the 3D space?
     
  11. Jul 28, 2015 #10

    HallsofIvy

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    Last edited: Jul 31, 2015
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