new iop: apply 3D LUT from file
Colour transformations using 3D LUTs (Look Up Table) are popular in cinematography but no so in photography (probably one of the causes is a lack of support for it in software). I use them a lot and I usually drop using Darktable for those cases and switch to Natron, but this solution is far from perfect (I love Darktable for many reasons).
LUT transformation have to applied in pipeline after basic exposure and colour correction and before some other luma and colour corrections.
AFAIK, ready to use implementation of this transformation is provided by OpenColorIO library via LookTransform function. It is used in most compositing programs (like Natron, Fusion, Nuke).
#1 Updated by Tobias Ellinghaus almost 2 years ago
- % Done changed from 0 to 20
- Target version set to Future
- Status changed from New to Triaged
As I wrote on the mailing list, OpenColorIO is a dependency that I feel is too big and opposed to our way of handling colors. But as LUT handling is quite easy anyway we don't need it in the first place.
The difficulty is that there are at least 3 places in the pipe where LUTs are commonly applied, the middle as you said, then as input color profile and also as a final place for grading. The final one may even just be applied to the display and not the exported image.
So while I'd like to have this, we first need a lot of input about all the places where we should support LUTs and only then decide if it is feasible.