[Cin] Plugins in integer or in float

Andrew Randrianasulu randrianasulu at gmail.com
Mon Nov 6 16:02:30 CET 2023

пн, 6 нояб. 2023 г., 11:49 Andrea paz <gamberucci.andrea at gmail.com>:

> I did some tests to see which of the major CC plugins use floats and
> which use integers.
> It turns out that only Blue Banana and Gamma support values above the
> range (0-1.0). Histogram Bezier reads values above 1.0 but does not
> use them, returning the usual clip.
> I start by showing the original image (png) where we can see details
> in the brightly lit window. In Compositor we don't see those details,
> getting only pure whites. So CinGG does not support HDR, as we already
> know (project setting to RGBA-FLOAT). However, even if we don't see
> them the details are there. To see them we have to do Tone Mapping,
> for example by decreasing the brightness levels until the values above
> 1.0 are back inside the range.
> With the Histogram plugin you can easily do this by lowering the white
> point along the vertical. No plugins show the details hidden in the
> white point except Blue Banana and Gamma. Since HDR is handled only in
> floating point (there are no values outside the range 0-255 or 0-1023,
> etc.), then I believe that all plugins work on integers except the two
> mentioned above.

this is a bit strange because I remember Adam's page showing raw file
processing where difference was there, in hv 2.x era  ....


oh, even 1.x era!


are you sure you have 16 bit per channel  png as input, with levels going
up above 255?

same with exr, from, for example Blender or Natron as input?

or may be you run into fact that values clips when processed by any but
those two plugins? Then there must be some bug preventing negotiation of
float colorbuffers for plugins somewhere ...

can you try another "lowering" tecnique, like creating 0.75 exr and
subtract it from overbright image as layer/track mode?

The test video can be found here:
> https://streamable.com/rh62t9

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