Reference Formats
LUT (.cube)
A .cube file is a plain-text lookup table format that maps input RGB values to output RGB values, used to apply consistent color grades or camera-log-to-display color transforms across video and photo software.
Extension
.cube
Full name
.cube 1D/3D Lookup Table
Introduced
2003 (created by Iridas); formal Cube LUT Specification version 1.0 published by Adobe in 2013
Vendor
Adobe (originally developed by Iridas; Adobe acquired Iridas in 2011 and published the spec)
What is inside the container
The file is human-readable text containing a header (LUT_3D_SIZE or LUT_1D_SIZE, optional DOMAIN_MIN/DOMAIN_MAX and TITLE lines) followed by rows of output RGB triplets, one row per input grid point. A 1D LUT applies the same curve independently to each channel, while a 3D LUT maps the full RGB cube and can therefore represent cross-channel color shifts that a 1D LUT cannot. It carries no embedded preview image or color-space metadata beyond what is stated in its header comments, so the intended input color space (e.g., a specific camera log profile) has to be tracked separately.
How to open it
For archives
Store the LUT alongside documentation of what input it expects (which camera log profile or working color space) and what output it targets, since the .cube file itself carries no enforced metadata about this. Keep the exact grid size (e.g., 33x33x33) and any DOMAIN_MIN/MAX values on record, because resampling or hand-editing a LUT without preserving those values changes its color mapping. Version LUTs by name rather than overwriting, as a look used on a finished production needs to remain retrievable exactly as it was applied.
The .cube format was created by Iridas in 2003 as a lookup-table container for its color grading software, aiming for interoperability across the color tools of the time. Adobe acquired Iridas in 2011 and subsequently published the Cube LUT Specification version 1.0 in 2013, formalizing the plain-text structure that had already become a de facto standard across grading and editing applications. Because the format is just text with a documented header and value rows, it was straightforward for other vendors to adopt without licensing friction, which is a large part of why it became the common LUT exchange format across DaVinci Resolve, Premiere Pro, Final Cut Pro, and Photoshop.
| Header field | Purpose |
|---|---|
| LUT_3D_SIZE / LUT_1D_SIZE | Grid resolution (e.g. 33 for a 33×33×33 cube) |
| DOMAIN_MIN / DOMAIN_MAX | Input value range the table covers |
| TITLE | Optional human-readable label for the look |
In a DAM context, .cube files function less like a finished visual asset and more like a reusable production tool: a single look LUT might be applied across an entire shoot or campaign to give footage or photos a consistent grade. The practical cataloging challenge is that a .cube file has no visual identity of its own — a thumbnail only makes sense if the DAM renders a reference image through the LUT to show what the look actually does, since two arbitrary LUT files look identical as plain text until applied to an image.
The other pitfall is color-space ambiguity: a .cube file’s header does not enforce what input color space it expects, so a LUT built for a specific camera’s log profile can be applied to the wrong source and produce a badly wrong result without any error being raised. DAM records for LUTs should capture the intended input log/color space and output target as explicit metadata fields, not rely on the filename alone, since LUTs get renamed and reused across projects long after that context would otherwise be lost.
Frequently asked
Who originally created the .cube LUT format?
Iridas developed the format in 2003 for its color grading tools; Adobe acquired Iridas in 2011 and published the formal Cube LUT Specification version 1.0 in 2013.
Why does a .cube file need a rendered preview image in a DAM, when the file itself is just text?
Because the LUT's values only mean something when applied to an image; without a reference frame processed through it, the file gives no visual indication of what color grade or look it produces.
What happens if a LUT built for one camera's log profile is applied to footage from a different camera?
The color transform will be applied to the wrong starting values, typically producing incorrect color and contrast, since .cube files do not enforce or validate what input color space they expect.
What is the difference between a 1D and 3D .cube LUT?
A 1D LUT applies an independent curve to each of the red, green, and blue channels, while a 3D LUT maps the full RGB cube and can represent color shifts across channels that a 1D LUT cannot express.
Should a DAM store the LUT's grid size as metadata?
Yes, along with any DOMAIN_MIN/DOMAIN_MAX values from the header, since these define the LUT's precision and value range and are needed if the LUT is ever resampled or converted to another format.
Can .cube LUTs be applied in Photoshop as well as video tools?
Yes, Photoshop can load a .cube file through its Color Lookup adjustment layer, in addition to its native use in video grading tools like DaVinci Resolve and Premiere Pro.
Is a .cube LUT the same thing as an ICC profile?
No. An ICC profile describes a device or color space's characteristics for color management, while a .cube LUT is a creative or corrective color transform applied intentionally, often for a stylized look rather than color accuracy.
Why version LUT files instead of overwriting them?
A LUT used in a finished production needs to remain retrievable exactly as it was when applied, so overwriting the file with a revised version would make the original look impossible to reproduce later.
Sources
- The .cube LUT format was first developed by Iridas in 2003; Adobe acquired Iridas in 2011 and published the Cube LUT Specification v1.0 in 2013 checked 2026-08-07 — RawCut - What Is a .cube File?
- The Adobe Cube LUT Specification defines the LUT_3D_SIZE/LUT_1D_SIZE header, DOMAIN_MIN/MAX, and RGB value rows checked 2026-08-07 — Adobe Cube LUT Specification Version 1.0 (PDF)
- .cube is the standard text format for 3D LUTs supported by Premiere Pro, DaVinci Resolve, and Final Cut checked 2026-08-07 — GitHub - parse-cube-lut (Iridas/Adobe Cube LUT parser)