[Bf-vfx] Color spaces

[Andrew Hunter]

Hey Everyone,

Great work! I'm really excited to see this in action!

On Wed, May 25, 2011 at 5:59 PM, Xavier Thomas
<xavier.thomas.1980 at gmail.com> wrote:
> This is fantastic.
>
> I don't think it need any more work in the compositor, where
> everything is supposed to be linear (except a conversion node for the
> rare case when it is not linear).

I think now would be a good time to formally define the working
internal working space of Blender. The word 'linear' only describes
gamma and says nothing of the color value system nor the primary
values.

> What would be needed is an option for all image/movie/sequence input
> to select the colorspace (one of those option shoud be "automatic"
> other enforcing a certain colorspace).

I would be hesitant to make anything color related automatic. Implicit
behavior, like blender's current assumption that all inputs are srgb,
leads to unexpected results.

My opinion is to make any conversions explicit, input, output or
display. That said, sane defaults should be provided.

> Then the same for saving image/movie sequence.
>
> Then add user preferences to edit/add colorspaces, or pack them into
> the blend file.

Packing into a blend file is a good idea but having color spaces be
part of the user preference panel removes much of the flexibility.
Much of the beauty of OpenColorIO comes from being able to point a
node at a profile and all the defined color spaces are there.

> Last but not least: Have user preferences that tells wich colorspace
> to use for each screen/display and use it to display images/compositor
> result, color pickers...

Again, I think this should be either an explicit part of the viewer
node or better the conversion node itself, not something hidden in a
preference dialog.


In addition, the existing attempt a color management within ImBuf (or
rather the Image node itself) needs to be ripped out.

In my mind the workflow would be as follow:

Input node=> Covert to scene linear => [work here] => Convert for
output => File Output
                                                                          \

     => Convert for display => Viewer

Furthermore, should we be assuming that the display output is or isn't
calibrated?

Cheers,

Andrew