Convert-cube-to-xmp

Converting LUTs (Lookup Tables) to (Adobe's profile and preset format) is a standard workflow for photographers who want to use cinematic color grades directly in Adobe Lightroom Photoshop's Camera Raw

. Because Lightroom does not natively support .cube files, they must be "wrapped" into an XMP-based Creative Profile Top Conversion Method: Adobe Camera Raw (ACR)

The most reliable and "official" way to perform this conversion is through Photoshop's Camera Raw filter. This process embeds the LUT data into an XMP profile. Open any image in Photoshop and go to Filter > Camera Raw Filter Access the Profile Creator : In the Presets/Profiles tab, hold Alt (Windows) Option (Mac) and click the New Preset (three-dot icon) Create Profile Load the LUT : At the bottom of the dialog box, check the Color Lookup Table box and navigate to your Name and Save

: Give your profile a name and assign it to a group. This saves an file to your computer's "Settings" or "Profiles" folder. Sync to Lightroom convert-cube-to-xmp

: Restart Lightroom Classic; the new profile will appear in the Profile Browser (Basic panel). Key Comparison: LUTs vs. XMP Import .xmp as presets NOT profiles - Adobe Community

Convert Cube to XMP: A Practical Guide

1. Color Space and Gamma

A CUBE file is designed for a specific input color space (e.g., Log-C, Rec.709, or Arri Log). An XMP profile in Lightroom expects a linear or Melissa RGB input.

The Rule: You must convert your Log CUBE to Rec.709 before converting to XMP, OR you must use a "Color Space Transform" within the XMP profile. If you don't, the converted XMP will look completely washed out and flat. Converting LUTs (Lookup Tables) to (Adobe's profile and

Method B — Photoshop + Camera Raw (manual, Adobe-only)

Use this if you have Photoshop and want to bake a LUT into an ACR profile.

Steps:

1. Prepare a neutral reference image (e.g., full-range gray ramp or color chart) at high bit depth (16-bit TIFF).
2. Open the reference image in Photoshop.
3. Apply the .cube LUT:
   • Use a plugin that can load .cube LUTs (some free LUT loader plugins exist) or use an Adjustment Layer that references the LUT via Color Lookup (Menu: Layer > New Adjustment Layer > Color Lookup > Load 3D LUT).
4. With the LUT applied, export a Camera Raw/Lightroom profile:
   • Use Adobe DNG Profile Editor or the built-in Profile tool:
     • Save the adjusted image as a DNG and use DNG Profile Editor to create a camera profile capturing the LUT effect. (This requires some familiarity with the DNG Profile Editor.)
   • Alternatively, use third-party scripts/plugins (e.g., ProfileConverters or 3rd-party LUT-to-DCP plugins) to bake into .xmp/.dcp.
5. Install the produced profile into CameraRaw/Lightroom as in Method A.

This route is more hands-on and may require trial-and-error to retain hue/saturation/contrast fidelity. Prepare a neutral reference image (e

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2. Input Format: .cube

• Standard format for 3D LUTs.
• Defines a 3D grid of RGB output values.
• Typically 17x17x17, 33x33x33, or 65x65x65.
• Simple text format with header lines:

  TITLE "My LUT"
  LUT_3D_SIZE 33
  DOMAIN_MIN 0.0 0.0 0.0
  DOMAIN_MAX 1.0 1.0 1.0
  0.000000 0.000000 0.000000
  0.031373 0.031373 0.031373
  ...
  

Background: Cube and XMP Formats

• Cube: A data format used for representing multidimensional data, commonly utilized in data warehouses and business intelligence applications. Cube data structures are designed to efficiently handle and analyze large volumes of data.

• XMP (Extensible Metadata Platform): An ISO standard (ISO 16684-1:2019) metadata framework that allows for the embedding and exchange of metadata across different systems and applications. XMP is widely used in various industries, including photography, design, and document management, to describe and manage metadata associated with digital assets.

Python Implementation

Here’s a reusable convert_cube_to_xmp(cube_dict) function using xml.etree.ElementTree.

import xml.etree.ElementTree as ET
from datetime import datetime
def convert_cube_to_xmp(cube):
NS = 
"x": "adobe:ns:meta/",
"rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
"dc": "http://purl.org/dc/elements/1.1/",
"cube": "http://example.com/cube/1.0/"

# Root
xmpmeta = ET.Element(f"NS['x']xmpmeta")
rdf = ET.SubElement(xmpmeta, f"NS['rdf']RDF")
desc = ET.SubElement(rdf, f"NS['rdf']Description", 
                     attrib=f"NS['rdf']about": "")
# Cube title
title = ET.SubElement(desc, f"NS['dc']title")
title.text = cube.get("cubeName", "UnnamedCube")
# Dimensions
dims = ET.SubElement(desc, f"NS['cube']dimensions")
seq = ET.SubElement(dims, f"NS['rdf']Seq")
for dim in cube.get("dimensions", []):
    li = ET.SubElement(seq, f"NS['rdf']li")
    li.text = dim
# Measures
meas = ET.SubElement(desc, f"NS['cube']measures")
seq_m = ET.SubElement(meas, f"NS['rdf']Seq")
for m in cube.get("measures", []):
    li = ET.SubElement(seq_m, f"NS['rdf']li")
    li.text = m
# Time range
if "timeRange" in cube:
    ts = ET.SubElement(desc, f"NS['cube']timeStart")
    ts.text = cube["timeRange"]["start"]
    te = ET.SubElement(desc, f"NS['cube']timeEnd")
    te.text = cube["timeRange"]["end"]
# Serialize
xpacket_start = '<?xpacket begin="\xef\xbb\xbf" id="W5M0MpCehiHzreSzNTczkc9d"?>'
xpacket_end = '<?xpacket end="w"?>'
rough_xml = ET.tostring(xmpmeta, encoding="unicode")
return f"xpacket_start\nrough_xml\nxpacket_end"