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Thread: color tuning

  1. #1
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    Default color tuning

    howwwwwwwww do ya DO EET ??

    I got my laser back (Mobile Beat Mirage - seems like a mk2 cuz of lock with EtherDream2 DAC)

    I've been trying different things having never done it before.

    Here's my scribbles so far...

    Code:
     hue rgb name        max=255     max=64      wtf ??
    *  0 200 red
      20 210 orange      too yellow  yellow:(    red too strong for green
    - 40 220 yellow
      60 120 lime        too yellow  too yellow  red too strong for green
    * 80 020 green
     100 021 green-aqua  too blue    too blue    blue too strong for green
    -120 022 aqua
     140 012 blue-green  too aqua    too aqua    blue too strong for green
    *160 002 blue
     180 102 purple      too pink    pinkish     red too strong for blue
    -200 202 magenta     pinkish     pretty good?
     220 201 darkpink    pinkish     pinkish     red too strong for blue
         222 white
         221 white-yellow  (these incr lum 120=>180)
         122 white-aqua
         212 white-magenta
    So I know I want white at the max settings that look white. AND at the min settings that look white.
    Red, Green, Blue don't require any tuning all by themselves obviously.
    And yellow, aqua(ok, cyan), and magenta are pretty easy to get close to.

    So I guess the trick is ORANGE and it's other hazy tertiary cousins...

    Can anybody help me out with this? This must have been tackled a kajillion times by a kajillion people.

    thanks iiiiiin advance !!

    ...Steve

  2. #2
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    Not sure what you are asking but you may need color correction curves. In other words, as your RGB values go from 0-255 you may need to actually send different values (non-linear) to your lasers.

  3. #3
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    Default

    I have no idea what you are asking

  4. #4
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    yes John - that's what i mean.

    so how do i come up with those curves?

    so far, i've been using a min and max for r, g, and b separately.

    but it doesn't seem like a plain linear interpreted value like that will work for me.

    i can get r,g,b and yellow,cyan,magenta no prob.

    but when i try for orange, lime, pink, purple they are frustratingly difficult to get...

  5. #5
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    swamidog is online now Jr. Woodchuckington Janitor III, Esq.
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    these curves will be different for every single laser projector. most modern laser show software has built in color envelope editors.

    Quote Originally Posted by stephenhazel View Post
    yes John - that's what i mean.

    so how do i come up with those curves?

    so far, i've been using a min and max for r, g, and b separately.

    but it doesn't seem like a plain linear interpreted value like that will work for me.

    i can get r,g,b and yellow,cyan,magenta no prob.

    but when i try for orange, lime, pink, purple they are frustratingly difficult to get...
    suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.

  6. #6
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    Quote Originally Posted by swamidog View Post
    these curves will be different for every single laser projector. most modern laser show software has built in color envelope editors.
    Ok, I get that it's different depending on the exact nm color and power levels, and the eye's affinity for green.

    But let's say I'm trying to make said curves. How do I go about it? Just guess?
    There must be some kinda procedure, eh?

  7. #7
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    Quote Originally Posted by stephenhazel View Post
    Ok, I get that it's different depending on the exact nm color and power levels, and the eye's affinity for green.

    But let's say I'm trying to make said curves. How do I go about it? Just guess?
    There must be some kinda procedure, eh?
    You allow the user to enter more than just min and max value for colors. Let them enter a midpoint, or multiple midpoints so that instead a line from max to min there is a curve. Then, based on the ILDA value that you are supposed to display for R,G, or B, you compute it using your color correct line.

  8. #8
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    Click image for larger version. 

Name:	colorcurves.png 
Views:	9 
Size:	36.2 KB 
ID:	53649This is what it looks like in GIMP -- it uses bezier curves between control points, separate curve per color.
    I would add additional curves if I had more than three primaries (laser lines).
    In projection, you just need a 256 entry lookup table for each color. How you generate the values is pretty open.Attachment 53648

  9. #9
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    If you want to get fancy, you could try this: http://ams.com/eng/Products/Light-Se...ensors/TCS3430

  10. #10
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    Hmmm, I've thought about it now.

    I'm thinkin 13 hues. The main 12 tertiary hues and white.
    So figure out rgb for brightest [red,orange,yellow,lime,green,cyan-green,cyan,cyan-blue,blue,purple,magenta,pink,white] i can do.
    Then again for the lowest power I can do in those hues.
    And then interpolate between THOSE.

    We'll see how it goes... I don't wanna get fancy with frickin bezier curves unless i REALLY have to... sigh.

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