[Tig] Universal Color Metadata challenge

[Jim Houston]

On Sep 4, 2007, at 6:21 PM, Stu Maschwitz wrote:
> I would appreciate any thoughts or
> feedback from this group.

> • Primary color correction using lift, gamma, gain, and saturation
> • RGB curves
> • Hue/Sat/Lum curves
> • Some number of layered "secondary" corrections that can be masked  
> using simple shapes, spines, and/or an HSL key

Hi Stu,

As far as the metadata challenge part goes, we are working on it
within the context of the ASC-CDL.   It took about 2 years to get
consensus of the vendors and participants to the '9 numbers'
approach for primary grades.   It is somewhat limited in scope because
of the need for FlexFiles and EDLs to also carry this data.
However, the XML container is flexible enough that the other
areas you mention could be carried in the XML format as well.

The difficulty is in getting all the vendors to treat certain
operations the same way.   Saturation is one we are still
working towards.  I would look at the current ASC-CDL as
being the camels nose under the tent.  Extensibility was
strongly desired with the CDL.

I would expect RGB curves and Hue/Sat/Lum curves to be
handled in the upcoming LUT format.

Masked secondaries are going to take a bit of time to
bring to a common standard. (How come there is no
common roto-splines standard?)

The need you describe is widely recognized, now it is just
getting everyone to act on it and drag the standard
features into exchangeable metadata.

Jim H.
jim.houston at mindspring.com
chair,  Academy/ASC LUT standard committee.
chair, Academy Image Interchange Framework committee