darktable denoise profile doesn't work on linear REC2020 tiff

Software darktable
1

Hi.
Denoise profile doesn’t seem to do anything on a linear REC2020 tiff produced by Rawtherapee.
Applying the same dp settings to the correspondent raw show a strong effect (as expected).
Have I missed something?
I would like to develop the tiff after applying capture sharpening on RT.
The following files are licensed under Creative Commons license.

TIFF file and xmp
https://drive.google.com/open?id=1kUgzqphNVzeuEbHbU7IoZhVtq2zkgZbd
IMG_6740.tif.xmp (4.4 KB) (dt 3.1.0)
IMG_6740.tif.out.pp3 (11.3 KB) (the way RT exported the tiff)

Raw file
IMG_6740.cr2 (11.8 MB)
IMG_6740_01.cr2.xmp (6.0 KB) (dt 3.1.0)

2

Hum, I suspect this tif is not considered as a raw file (and it really isn’t, right?) and, as such, denoise profiled is not being applied.

3

The key is in the profile. You need to use the profile on data that are in the same state as the ones used to produce the profile. So, if your profile has been produced for one specific sensor RGB space, applying it in any other RGB space will fail.

Same applies to LUTs, lens profiles, even colour profiles… You always need to use input data that are in the same state as the input used to create the profile (so you possibly need to adapt your data).

It’s theoriticaly possible to encode your pixels from Rec 2020 back to camera RGB, but it’s not implemented in the UI.

4

Humm, I see, thanks for the explanation.

So, no matter the profile I choose when exporting the file in RT (srgb, rec2020, aces, etc), it won’t be the same as the camera’s rgb space, so, in practical terms, denoise profile won’t work.

So I guess I’ll have to wait for the image doctor to come around (soon?) if I want to apply sharpening as good as the amazing Rawtherapee capture sharpening…

5

Maybe denoise in darktable, export as tiff, then open in RT and sharpen?

6

Capture sharpening in RT only works on raw files.