[Cin] Adobe Premiere (2021) and HDR

[Andrea paz]

CinGG is already capable of reading HDR images, as I believe any
program that works in floating point. Just load an HDR image and then
read the values in the white with the eydropper tool, to confirm it.
What to do in CinGG if we are dealing with HDR media? If we have an
HDR monitor I don't know, in fact if anyone has one, that would be
useful information. If we have an SDR monitor all we can do is tone
mapping and bring everything back to SDR. The trouble is that in CinGG
the plugins that work for tone mapping are only the primary color
correction plugins, that is, they affect the whole frame. In this way
we are able to reveal details in the highlights but the midtones and
shadows become hopelessly pure black. It would take secondary color
correction tools, i.e., capable of acting only in certain areas of the
image. Unfortunately, CinGG's two main plugins, namely 3 color way and
curves (contained in Histogram Bezier) do not support HDR values. My
old attempt to “unlock” the Value slider in 3 color way was disastrous
because it destroyed the functionality of the shadow color wheel. I
don't know why. With Histogram Bezier curves one could lock the shadow
and midtone values and lower only the highlight values, but, as
mentioned, this is not possible. This is easily seen by trying tone
mapping: for an SDR image or a clipped HDR image: homogeneous white of
value 1.0 becomes homogeneous gray of value less than 1.0. So an
unnecessary intervention. In an HDR image, the white value above 1.0
(which we see as homogeneous white = 1.0, however) leads to detailed
gray values that are no longer homogeneous, thus reconstructing the
content present in the white.

How HDR values relate to color spaces, I just cannot understand.