On 04/24/2016 12:30 PM, Tobias Ellinghaus wrote:

https://mail.gnome.org/archives/gimp-developer-list/2016-April/msg00098.html:

It's hardcoded to export 32bit float EXR as linear Rec709 after opening up your regular darktable. Did you manually select the Canon or Nikon format in the open dialog?

It would be nice if the darktable plug-in were modified to allow users to choose their preferred output space.

But currently darktable does seem to force output to be in the darktable version of linear gamma Rec709 (which isn't equivalent to GIMP's internal linear gamma sRGB color space - https://mail.gnome.org/archives/gimp-developer-list/2016-April/msg00116.html -, but hopefully this can be changed).

Right now GIMP is an "sRGB only" image editor. But this situation surely won't last forever. Having a raw processing plug-in that only allows to export in one color space (especially a color space that doesn't match the GIMP built-in sRGB color space) seems to be a step in the wrong direction.

Also, only some GIMP operations are "sRGB only". Many operations work just fine using any RGB working space chromaticities.

Presumably at least some GIMP users will sometimes want to edit their interpolated raw files in RGB working spaces other than sRGB, and GIMP does allow this to happen. So it doesn't make sense that the darktable plug-in prevents users from exporting the image in the user's chosen RGB working space.

Best,
Elle

On 04/27/2016 05:43 PM, Tobias Ellinghaus wrote:

Am Mittwoch, 27. April 2016, 12:00:32 schrieb Elle Stone:

On 04/24/2016 12:30 PM, Tobias Ellinghaus wrote:

https://mail.gnome.org/archives/gimp-developer-list/2016-April/msg00098.html:

It's hardcoded to export 32bit float EXR as linear Rec709 after opening up your regular darktable. Did you manually
select the Canon or Nikon format in the open dialog?

It would be nice if the darktable plug-in were modified to allow users to choose their preferred output space.

Yes.

But currently darktable does seem to force output to be in the darktable version of linear gamma Rec709 (which isn't equivalent to GIMP's internal linear gamma sRGB color space - https://mail.gnome.org/archives/gimp-developer-list/2016-April/msg00116.html -, but hopefully this can be changed).

Should be fixed, see the other thread. Once you confirmed that the profiles are fine now we will release darktable 2.0.4.

Yes, the profiles are fine.

Right now GIMP is an "sRGB only" image editor. But this situation surely won't last forever. Having a raw processing plug-in that only allows to export in one color space (especially a color space that doesn't match the GIMP built-in sRGB color space) seems to be a step in the wrong direction.

The reason I chose linear sRGB is that

1) we are exporting to EXR as the intermediate file, so we need a linear profile 2) GIMP seems to work best with sRGB images so far, so I used the linear version of that.

I agree that it would be nice to have some choice there. Would default export to linear Rec2020 be better? Still hard coded, but a wider gamut. It seems GIMP asks about converting the colors anyway, so for people that want to work in sRGB that's just one click away.

At this point in time and given the hard-coded sRGB parameters in the babl/GEGL/GIMP code base, if the darktable plug-in can't be easily modified to provide users with a choice of export profiles, then converting the image to linear gamma sRGB seems to me to be the right choice (even though I'd love to suggest using linear Rec2020).

If a user wants to then convert the image to another RGB working space, that conversion can be done in GIMP, as you say "just a couple of clicks away". This assumes the exported darktable OpenEXR file doesn't clip out of gamut channel values, which I'm pretty sure it doesn't - at least the "out of sRGB gamut" channel values in my sample CR2 file were not clipped.

Best, Elle