Gradient Map/Reverse Gradient Map Script

Discussion in 'Other' started by fencepost, Mar 20, 2010.

  1. fencepost

    fencepost Member

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    Glad you were able to get some results!

    Not necessarily. You can apply a gradient map directly to the active layer OR, if you're using my gradient map script, apply it directly to all layers in the image. However, it appears that the tutorials I provided links to always apply the gradient mapping to duplicate layers and adjust opacity. It really depends on what effect you're trying to achieve.

    Correct. In order for the mapping to take place, you have to have something other than transparency to work with. I think people get the impression that gradient mapping is a similar thing as adding a gradient to a layer. However, the only way they are similar is that they both use gradients. You can add a gradient to any layer (transparent or filled) and set the opacity, blend mode, gradient shape, etc. However, the gradient mapping simply exchanges existing colors within a layer using the chosen gradient. There are no options to set opacity, blend mode, shape, etc. because color 'A' in the gradient is exchanged with color 'A' in the layer. Unfortunately, you can't specify which color in the gradient should replace the color in the layer. However, I believe there are other techniques in GIMP to accomplish that, but that's not something I'm an expert in.

    Don't know if this helps or not, but it looks like you're on the right path.

    Art
     
  2. virtualTune

    virtualTune Active Member

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    now, i figured i would get the same results if i just make a new layer. add the desired gradient. set mode to overlay and play with opacity. so there is no need to make the gradient mapping. 8O
     
  3. fencepost

    fencepost Member

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    No, they are not the same thing. Try it and see. Gradient mapping is a color exchange and adding a gradient & changing the blend mode/opacity is just overlaying with a gradient. I've used your signature as an example.

    Incandescent gradient placed on a new layer (linear shape, Overlay mode, 100% opacity)

    [​IMG]

    Incandescent gradient map

    [​IMG]
     
  4. David Wood

    David Wood Active Member

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    That's right, adding a gradient to a layer isn't gradient mapping.

    In gimp, when gradient mapping, the foreground color will be the dark colors in the image, and the background color is going to be the light areas.
     
  5. virtualTune

    virtualTune Active Member

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    though the same effect could be achieved with gradients..?!

    that was a good example fencepost! thank you. you should make some tuts. u're really good att explaining stuff! ;)
     
  6. David Wood

    David Wood Active Member

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    I'm working on one. ;)
     
  7. virtualTune

    virtualTune Active Member

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    IMO (!!!!!) fencepost is easier to understand though..... ::)
     
  8. fencepost

    fencepost Member

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    Probably not easily. Remember, you're exchanging one color for another. With a gradient overlay whatever color is above the layer is just blending with the layer below. Exchanging does NOT equal blending.

    I've written a few in my day.....http://fence-post.deviantart.com/galler ... -Tutorials

    Art
     
  9. fencepost

    fencepost Member

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    I think David will do a good job. Don't be too hard on him. I don't write many tutorials these days....my joy is scripting.
     
  10. virtualTune

    virtualTune Active Member

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    :p i am hard on him cuz he behaves like my big bro(which is fine cuz i have no sibblings) ;)
     
  11. bladesonic

    bladesonic Member

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    Gimper has always been more tight-knit than the larger forums, where you get the internet equivalent of cliques.
    @Fencepost: I tried out your script on my latest 'piece' (if you can call it that), and the results were very nice. Thanks much =D
     
  12. David Wood

    David Wood Active Member

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    Oh man, I was going to record the tutorial but Dad, was annoying me on purpose, tomorrow morning I should be able to record the first part. :)
     
  13. fencepost

    fencepost Member

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    You're welcome. Glad it helped.

    Art
     
  14. David Wood

    David Wood Active Member

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    *bump*
    You all know I recorded the tutorial, I'm putting up the file in a zip on the first page. :)
     
  15. velvet

    velvet Member

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    very useful script thankyou
     

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