Hi!

Hald is a 2D representation of a 3D .cube file that map pixel => pixel.

Given a HALD color template at specific definition and a tuned image
we can deduce the applicable LUT.

https://github.com/SirSerch/lut-creator-js is one approach.

I would like to generate LUT from libvips.

LUT Generation

// internal comparaison based on passed HALD size
// should be 25, 64 or 144 to match internal HALD
inferLut(myTunedHald_Size_25, samples{2...144});

// User pass its own HALD as reference
inferLut(imageSource, imageTuned, samples{2...144});

This will generate a .cube file.

Lut from Vips chain of operation;

ref = hald25();
transform = hue(contrast(ref, 25), 30);
generatedLut = inferLut(ref, transform, 64);

Apply LUT

A huge bonus would be to be able to apply .cube to image
as it the mechanics is already in the framework.

rs = applyLut(ref, generatedLut); 
// rs equals more or less ref

The feature is ubiquitous in all softwares and languages.
LibVips seems the best place to benefit for it :)

Thoughts about that?

Thank you!