[Bf-funboard] G'Mic Filters in Compositor?

[Troy Sobotka]

On Sun, Jan 31, 2016, 6:07 PM Zauber Paracelsus <zauber at gridmail.org> wrote:

What does scene-referred mean?
>

It refers to the model that stores image values. Contrast against display
referred.

A scene referred image has no notion of white or black, with a range of
values from zero to infinity. Much like a scene one wishes to photograph.
Typically encoded as scene linear.

Display referred (aka device or output referred) places a minimum
(typically zero) and a maximum (typically one) value on the dynamic range
of the output context. Also typically stores values nonlinearly.

The differences between the two models will influence the algorithms and
blend modes where a unity point can't be assumed. See display referred
screen, dodge, and burn formulas according to the Adobe PDF
specification[1]. They do not work correctly on scene referred imagery.

This is of particular importance to Blender as Cycles renders scene
referred imagery, and the compositor must be equipped to deal with it.

Further reading:

* The Visual Effects Society's handbook on cinematic colour at
http://cinematiccolor.com/
* The Visual Effects Society Handbook
http://www.amazon.com/VES-Handbook-Visual-Effects-Procedures/dp/0240825187/ref=sr_1_1?ie=UTF8&qid=1454307741&sr=8-1&keywords=ves+handbook+of+visual+effects
* ILM's OpenEXR color management proposal
http://www.openexr.com/OpenEXRColorManagement.pdf
* The Art of Digital Color
https://www.fxguide.com/featured/the-art-of-digital-color/

With respect,
TJS

[1] http://www.adobe.com/devnet/pdf/pdf_reference.html

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