LUT-Utility

A utility to

• generate identity/neutral LUT images of different types (HALD CLUT or Unwrapped Cube as used in ReShade) as base for your edits
• convert these types of LUT images to .cube LUTs of different sizes (smaller or equal than the input size) and to
• apply these LUTs to images.

A HALD CLUT looks like this:

A Reshade LUT looks like this:

Use-case 1: Export your edited looks/grades (from any editing software) as .cube

You may have a camera like the Lumix S9 or some other software that requires .cube LUTs of a specific size (e.g. 33) for image and movie grading.

1. Create an identity HALD image:

Usage: lut_utility.exe generate [OPTIONS] --format <FORMAT> --cube <CUBE> --output <OUTPUT>
Example: lut_utility generate -f H -c 144 -o identity144.png

Options:
  -f, --format <FORMAT>        The format of the identity LUT to generate (hald or unwrapped-cube) [possible values: hald, unwrapped-cube]
  -c, --cube <CUBE>            The base cube size for LUT generation (is same as level^2 for HALD). Affects density and image size: Image dimension = HALD: √(cube³) x √(cube³) UNWRAPPED CUBE: cube² x cube. Practical range: HALD: 1-400 UNWRAPPED CUBE 1-64. Higher values generate very large images
  -o, --output <OUTPUT>        Output filename for the generated PNG image. Must have a .png extension
  -b, --bit-depth <BIT_DEPTH>  Desired bit depth for the output PNG (8 or 16). Only applicable for Unwrapped Cube format [default: 8]

2. Use this generated png in your editing software to apply your looks and grades. Note:

• Only color grading and brightness changes can be applied to this HALD image.
• sharpening, bluring, grain, lens corrections, noise reduction, cropping will destroy your HALD image and can NOT be used as LUT.

3. Save the image with your grades applied to a lossless PNG "mygrade-hald144.png"

4. Convert your graded HALD image to .cube

Usage: lut_utility.exe convert [OPTIONS] --input <INPUT> --output <OUTPUT>
Example: lut_utility convert -t 32 -i mygrade-hald144.png -o mygrade_cube32.cube

Options:
  -i, --input <INPUT>              Input LUT image filename (.png). Dimensions will determine LUT type (HALD or UNWRAPPED_CUBE)
  -o, --output <OUTPUT>            Output .cube filename (.cube)
  -t, --target-cube <TARGET_CUBE>  Optional target size for the output .cube file (e.g., 32, 33, 64). Must be <= the input LUT's native cube size

5. or preview your grade on any image

Usage: lut_utility.exe apply --lut <LUT> --input <INPUT> --output <OUTPUT>
Example: lut_utility apply -l mygrade-hald144.png -i my-ungraded-image.jpg -o mygraded-image-with-mylook1.png

Options:
  -l, --lut <LUT>        Path to the LUT file (.png or .cube)
  -i, --input <INPUT>    Path to the input image file (.jpg or .png)
  -o, --output <OUTPUT>  Path to save the output image file (.png)

Use-case 2: Batch convert/apply alot of downloaded luts (New with v0.2.0)

This will convert all LUTs in input folder to cube LUTs in output folder preserving input filename and directory structure.

Usage: lut_utility convert [OPTIONS] --input <INPUT> --output <OUTPUT>
Example: lut_utility convert -i input\ReShadeLUTs -o output\CubeLUTs -t 32 -b

Options:
  -i, --input <INPUT>              Input LUT image file (.png) or a directory containing .png files for batch conversion
  -o, --output <OUTPUT>            Output .cube filename (.cube) for single file conversion, or output directory for batch conversion
  -t, --target-cube <TARGET_CUBE>  Optional target size for the output .cube file (e.g., 32, 33, 64). Must be <= the input LUT's native cube size
  -b, --batch                      Enable batch processing mode. Input and output must be directories

This will apply all LUTs in LUT (-l) folder to this one image (0424406328.jpg). The files will be stored as PNG in output\0424406328\ preserving LUT filename and directory structure.

Usage: lut_utility apply [OPTIONS] --lut <LUT> --input <INPUT> --output <OUTPUT>
Example: lut_utility apply -l input\HaldCLUTs -i input\0424406328.jpg -o output\ -b

Options:
  -l, --lut <LUT>        Path to the LUT file (.png or .cube) or a directory containing LUT files for batch application
  -i, --input <INPUT>    Path to the input image file (.jpg or .png). This remains a single file in batch mode
  -o, --output <OUTPUT>  Path to save the output image file (.png) for single LUT application, or output directory for batch application
  -b, --batch            Enable batch processing mode. LUT input must be a directory, output must be a directory

Links

Public free LUTs:

• https://github.com/cedeber/hald-clut
• https://gmic.eu/color_presets
• https://www.on1.com/free/luts/
• https://www.cyberpunk2077mod.com/cyberpunk-lut-pack/
• https://lut.tgratzer.com/

Online Tools

• https://lut.tgratzer.com/
• https://www.color.io/free-online-lut-converter
• https://colorizer.net/index.php?op=3dlut_tools
• https://cameramanben.github.io/LUTCalc/LUTCalc/index.html

Specs

• https://www.quelsolaar.com/technology/clut.html