For PatternSpace 2.0 on macOS. LUT Tools is in beta. Building and inspecting chains and preparing exports are available in PatternSpace Free. Writing LUT or ICC files requires PatternSpace Pro. Review the current format and operation limits below before preparing a deliverable.
A workbench for LUTs you already use
A lookup table maps input RGB values to output RGB values. In a calibration workflow, a LUT may contain a display correction; in an imaging workflow, it may contain a look or a technical transform. The filename alone does not tell you which role it serves.
PatternSpace’s LUT Tools lets you import supported LUTs, combine transforms in a node chain, apply numerical adjustments, inspect sampled behavior, and prepare a result for a destination format and grid. Imported files remain unchanged; export writes a separate result.
Open Tools → LUT Tools (Beta)…. Use the source’s Create option for a 1D, 3D, or Mixed identity transform, or Import an existing file. An identity passes values through unchanged, so the operations you add determine the result. Mixed sources combine independent 1D shapers with a 3D cube.
Choose the right operation
Compose: apply transforms in sequence
Compose feeds the result of the chain above the node into its Input-B branch. For transforms A then B, the result is B(A(RGB)). Reversing that order generally changes the result. A branch can contain its own operations before it rejoins the main chain.
Only compose LUTs whose input and output meanings are compatible. A normalized 0–1 domain does not identify a color space or transfer function. A log-to-display transform and a display correction need the correct order and signal interpretation; format conversion does not infer those choices.
Adjust: make explicit numerical changes
The Adjust node applies input scaling → ASC CDL Slope, Offset, and Power → saturation → output scaling. Use it for known adjustments to the transform, keeping the imported source intact. These controls do not calculate a calibration from measurements.
An adjustment can remain 1D when its Slope, Offset, and Power values match across channels and saturation and scaling are neutral. Other adjustments bake to 3D; the chain’s dimensionality also depends on the source and other operations.
Subtract and Invert: use with care
Subtract applies an approximate inverse of its Input-B branch to the chain above it. It does not subtract corresponding RGB table entries. Invert attempts to reverse the complete transform above the node.
1D inversion requires monotonic channels with usable spans. 3D inversion uses a numerical solution. Clipping and many-to-one mappings lose information: if two inputs become the same output, an inverse cannot uniquely recover both. A finite grid introduces additional approximation. Review these results in the intended workflow rather than treating them as guaranteed reversals of a calibration.
Inspect the transform before export
An Inspect node reports on the chain immediately above it and leaves the transform unchanged. Each chain or branch can contain one Inspect node. The compact gray-axis plot shows the sampled red, green, and blue responses for neutral RGB inputs.
- Verdict: Clean means the sampled report found no neutral-axis reversal, out-of-range output, or non-finite output. Check means at least one of those conditions needs review.
- Monotonicity: identifies a sampled channel reversal along the neutral axis.
- Clipping: reports sampled output outside 0–1. It does not detect every possible loss of information or every clipped plateau.
- Neutral drift: the largest sampled difference between red, green, and blue along the neutral axis.
- Effective gamma: a best-fit power response along the sampled neutral axis, when a fit is available.
Clean does not mean calibrated. These are RGB-space diagnostics, not Lab ΔE values, and they do not measure a display. A deliberate look can alter neutral balance; a technically clean transform can still be inappropriate for the signal or monitor you intend to use.
The current beta does not provide a before/after image preview or a rotatable 3D gamut visualization. Evaluate the exported transform in compatible target software and use measurements when judging calibration accuracy.
Convert formats without losing sight of the transform
PatternSpace identifies supported structures from file contents. A .3dl or .cube extension alone does not guarantee compatibility. If the contents match more than one supported interpretation, select the intended format.
| Family | Scope and limitations |
|---|---|
| Cube | 1D/3D, with IRIDAS, Resolve, and Nucoda dialect recognition. Non-default Resolve input ranges are reported as omitted metadata; the canonical model does not remap those ranges. |
| 3DL | Autodesk/Lustre/Flame-style, Assimilate, and uniform same-range vertex-list structures. Non-zero-base LG and cross-range vertex/output variants are not supported. Review dropped-shaper diagnostics for Autodesk files. |
| CLF | Scalar/RGB LUT1D, LUT3D, and uniform shaper-plus-cube structures with 32f outputs. Range, Matrix, CDL, half-domain/raw-half, and other unsupported structures are rejected. Omitted source metadata and interpolation preferences are reported. |
| Other LUT formats | Quantel 1D/3D, LUTher 3D, RED Camera 1D, CineSpace CSP, Nucoda CMS, Truelight Cube, and IRIDAS Look. Available export choices depend on the chain and the format’s supported structure. |
| ARRI Look | ALF1, ALF2, and ALF4 import only, with the fidelity limits described below. ARRI Look export and ALF4c are not supported. |
Compatible native shaper-plus-cube stages can be preserved when the destination supports them. Other conversions require baking or resampling. Review the preparation report for metadata loss, approximation, and range issues. Supporting a file format does not certify a device or provide a hardware upload workflow.
ARRI Look import: know what is represented
ALF1 imports its tone-map table; the full camera processing chain, CDL, and printer lights are not reproduced. ALF2 and ALF4 import a 33³ table and compose applicable CDL before that table. ALF4 Look Intensity and target color-space information are exposed as metadata; intensity is not applied. Sampling can differ from a camera’s processing between vertices.
Use these imports to inspect and work with the supported transform components. Do not assume that a converted file exactly reproduces the camera look.
Prepare, review, export
- Finish the chain. Every source and branch must load successfully. Failed or loading operands are not silently skipped.
- Select Export. Choose a supported destination format and grid that match the receiving application or device.
- Choose Prepare. PatternSpace evaluates the chain for that destination, encodes it, reads the bytes back, and verifies the prepared result.
- Review the report. Check differences, omitted metadata, and any compatibility diagnostics. More grid points do not recover information already lost in a source LUT.
- Export a separate file. Writing the file requires Pro. Source and operand files are protected against overwrite. Changing the chain or export settings requires preparation again.
Byte read-back checks the prepared file against the expected conversion. It is not a visual evaluation, measurement of display accuracy, or guarantee that another application will interpret every format option identically.
ICC export, display profiles, and VCGT are different
The ICC Profile destination in LUT Tools writes an ICC v4 RGB→RGB DeviceLink. It bakes the chain to a fixed 33³ table and stores the look transform in A2B0. This is for compatible software that can apply a DeviceLink transform; it is not a conventional display profile to assign in macOS.
| Output | Purpose |
|---|---|
| LUT file | A transform loaded by compatible software or hardware, according to that destination’s requirements. |
| ICC DeviceLink | An RGB-to-RGB transform applied in software with DeviceLink support. Use a compatible conversion workflow, not ordinary profile assignment. |
| Display ICC profile | A description of a display’s color response. Build and manage these in the separate ICC Profiles workbench. |
| VCGT | Per-channel video-card calibration curves. These cannot carry arbitrary 3D color mixing or replace the DeviceLink look. |
Include VCGT adds supported 1D calibration curves separately from the 3D look and is off by default. Clip out-of-range clamps values to 0–1 before 16-bit encoding; preparation still reports the affected samples. An existing compatible RGB→RGB DeviceLink can supply base metadata, and supported tags can be reviewed before export.
Exporting a chain does not apply it to a display or to DeckLink output. For temporary display calibration, profile assignment, and restore, use Tools → ICC Profiles… and follow the ICC Profiles guide.
Use the beta in a calibration workflow
Keep the measurement source, the correction transform, and its destination explicit. Create the correction in your calibration software, use LUT Tools for supported inspection or transformation tasks, then load the result in the intended destination and measure again. Retain the original file and the settings used for the conversion so you can reproduce the result.
Start with free preparation to check whether your files and desired destination fit the current beta. See PatternSpace Pro for export access, the calibration guide for the full workflow, and the DeckLink SDI guide for hardware patch output.