GIMP - How to apply 3D LUT?

Honestly, coding an interactive 3d clut manipulation is not in my plans :slight_smile: It’s a really big amount of work.
But, I’m preparing some advanced 3D CLUT preview for the filter, this should be enough I think.

Version 3 of this filter is now available :slight_smile:
It includes more advanced options, as well as a useful 3D visualization tool for the CLUT.


This is amazing! :smile:


@David_Tschumperle, Maybe I am asking too much, please then forgive me. The science for this awesome stuff is realy beyond my knowledge. Despite my lack of expertise, new ideas are popping up continuously in my mind.

Now you can replace source colors with target colors. Then there is interpolation with “3d solidify”. Is that correct?

Would it be possible to replace a source part of the color spectrum with a target part of the color spectrum?

@iarga, no problem, any idea is good to take. As long as I’ve the choice to choose which idea seems doable in a fairly quick time :slight_smile:

I’m not sure I understand your concern. The interpolation makes actually a lot of more or less wide range of colors changing to another range of colors, so it already matches one RGB region with another one.

I think I understand it a little bit. With 8 keypoints this range is wider then with more keypoints. Also you can change the keypoint influence.

To make my question more clear: “Is there another way to have influence on the wideness of this range of colors changing to another range of colors?” I would like to have the possibility to change the wideness of this range, for each color seperately.

edit: So I am asking to have more influence on this interpolation for seperate source colors and target colors.

From what I see when playing with the filter, it is really interesting to add several keypoints in the ‘lock mode’ (thanks for that wonderful idea @Iain!) , close to the color you’ve changed, to limit the range of a transformation for a single color.
For instance, I’ve been able to change only the background color on this example, while keeping the skin mostly unchanged :

Many keypoints around skin colors have been set in ‘lock mode’, while the keypoints around the green are in ‘replace’ mode.


Are there also ways to extend the range of a transformation for a single color?

Well, in a sense yes, you just have to avoid placing keypoints around.

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You can add several key points throughout the range of tones you want to change and set them to the same or similar target colours

Eg orange to green and yellow to green

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You understand me exactly. But I am a little bit lazy. So instead of several keypoints, I thought about one range you could set with sliders. So you could choose a start point and end point on a slider. A little bit like setting a range in LightZone (there you choose a color and set a range for light values) or like “Rotate Colours” in GIMP, altough the last isn’t with sliders but with two clocks, because of the continuity of the color spectrum.

“My” sliders would definitely clutter the whole UI. :smile:

Defining an entire closed region in a space like RGB with sliders… well, Good luck :slight_smile:

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Thank you for your patience. I begin to understand the complexity.

Now I’m in the LUT mode too. I’ve googled a little bit about LUT tables and found this tool. It has some really nice tools, perhaps someone is interested in copying them. :wink:

Why not buy it? I’m sure Oleg Sharonov will appreciate that. But maybe you could friendly ask him to make a FOSS-plugin for gimp? :wink:

Why not buy it?

  1. It doesn’t run on Linux.
  2. I only use FOSS.
  3. I don’t need it, I would only play with it.
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@David_Tschumperle, the filter has three actions: “Ignore”, “Lock source” and “Replace source by target”.

Is it possible to have a 4th option: “Replace source by gray target”? In which the gray target has the same value as the source color?

‘value’ as in HSV ?
I’m curious, but for which case you want to do that ? B&W conversion ?

For color correction. So if you know something is gray, you can make it gray.

edit: Iain is right. (see below) This is unnecessary. Thank you David.

Something strange happens with my color picker (cursor):