#20675 (Feature Request) 3D LUT maker – please add support for ICC profiles with 4096 points gamma curves and for Grayscale ICC profiles

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Created by _ shijan

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Currently 3D LUT maker don’t support ICC profiles with 4096 points gamma curves.

It also don’t support v4 ICC profiles with parametric gamma curves.

It also don’t support 1D grayscale ICC profiles.

It also can not generate 1D (gamma only) LUTs.

It possible to add this enchenced functionality in future versions? It will help people to generate 1D LUTs for different gamma correction purposes with better presicion and better resolution.


5 comments on “3D LUT maker – please add support for ICC profiles with 4096 points gamma curves and for Grayscale ICC profiles”

  1. Currently 3D LUT maker don’t support ICC profiles with 4096 points gamma curves.

    It does support up to 4096 curve entries per channel. Note that the accuracy difference between 4096 points and 1024 points is effectively non-existent (e.g. sRGB curve with 1024 vs 4096 points dE 2000 avg = 0.0005, peak = 0.004).

  2. It is strange. Here is my workflow: I try to generate series of accurate 1D LUTs for my workflow with scanned negatives (Linear to L* , L* to g2.2 and so on…) As as source i try to use these Elle Stone’s ICC profiles pack https://ninedegreesbelow.com/photography/lcms-make-icc-profiles.html But when i generate LUT with 3D LUT maker i got error message.

    I can only use 3D LUT maker with color ICC profiles generated Synthetic ICC app. I generate 65x65x65 3D LUT .cube with 3D LUT maker. Next with other app i convert it to 1D LUTs, and as a final result i got 1D LUT with only 65 points gamma curve. It works, but when i look as it’s curve, it looks very inaccurate and low resolution compare to native 256 1024 points 1D LUTSs.

    So probably my ticket requrst is rather complex. Is it possible to add option to allow to generate/import/export 1024 or 4096 points ICC profiles and LUTs with your apps without loss of resolution? Or at least option to generate 1D LUTs  to keep 256 or 1024 points curve on final export?

  3. For example ,in other apps there is usually an option to choose between 1D and 3D .cube LUT

     

    Here are also examples of 64 points resolution LUT from my previous post vs native 1024 points 1D LUT generated in other app.

  4. After some experiments i figure what cause error with profiles from Elle Stone’s ICC pack. Those profiles have additional description field with large amount of text and web address links to pdf document. When i removed that info and saved changes, i was able to use these profiles in 3D LUT maker without any problems.

  5. But my request for high resolution 1D gamma curve transformation support is still active. 1D  LUTs gamma convert tool with 1024 or 4096 precision is must have for 3D LUT maker app.

    There are other free apps like LUTCalc and commercial Lattice that can transform high resolution gammas, but those apps also don’t support L* gamma

    Here is real life usage example. L* gamma curve is perfect for inverting film negatives. For most accurate results film negative scanned in linear gamma should be inverted before transformation to working color space. Invert tool don’t works in linear gamma as it should, so we need to transform Linear to L* gamma, next do invert, and next transform back from L* gamma to Linear.
    If instead L*gamma we use sRGB or something like power function 2.2gamma, invert will produce less accurate tonal results and will shift color values after invert.

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