Color Management as compositing nodes - possible?

Support Compositing and Post Processing
#1

Hi,
i was wondering if it is possible to have the color management functions under “Properties -->Scene --> Color Management” as a Compositor node function.

The color management - and in particular the film emulation - helps a lot to gain a good image look, but it has no option the control the amount of the changes. If it would be possible to have it as a compositing node, the film emulation look could be mixed into the original image by using a 0…1 factor, or control it with further options.

Does anyone know if it is possible to do so? Some Help would be nice.

regards,

Karl Andreas Groß

#2

Film profiles are 3D LUTs, so to use them in compositor we need a LUT node. It is not a difficult thing to implement, but it is not there yet.

All other things (gamma, exposure, rgb curves) can be used in compositor right now.

#3

It would be simple enough, I think, if users added only one LUT node at the end of their comp.

It will be more complex where people are combining sRGB and RED log inputs with 20% of one film look and 40% of some other film look from different parts of their render.

I think these kinds of transforms won’t be easy to handle correctly, and this perhaps partly explains the current implementation.

#4

The correct handling won’t be easy for user, not from technical side. In Nuke for example, one can do all kind of acrobatics with LUTs, nonlinear encodings and color spaces and it all works if you are able enough to sort it out in your head.

Applying the same LUT to sRGB and RedLog will give different results, it is expected. It is up to user to prepare the input for LUT, each LUT has very specific “needs” for its input to do its job correctly because they are dumb (meaning LUT has no knowledge if it is applied to values that will produce a meaningful result or not).

#5

Hi Guys,
thanks for the reply - it is currently not possible to do node based film emulation in the compositor. If it would be in trunk in the near Blender Future, it would be really great.

until then i will stick to my current workflow which is mot very elegant, but for my works ok and it is like so: Render the image without film emulation, do all necessary compositing, save the image. Then do the compositing again, but this time with film emulation activated. then take both images - the one with film emulation and the unchanged one - into Gimp or Photoshop, and the use both images as layers for mixing in whatever stile.

Thank your for helping out!