GNOME Bugzilla – Bug 786100
RAW plug-ins limited to Rawtherapee / Darktable
Last modified: 2017-08-10 22:59:40 UTC
Using GIMP 2.9.5 from 'buntu ppa and kubuntu 16.04 Limiting RAW import to either Darktable (DT) or Rawtherapee (RT) came in a couple of weeks ago. Up to then the nufraw gimp plugin https://sourceforge.net/projects/nufraw/ compiled for Gimp 2.9.5 worked well. This small (5 MB) plug-in nufraw-gimp still works but only when I open the RAW image externally using the stand-alone nufraw (another 5 MB) Can the restriction on only DT/RT be lifted. These are fine applications but comparatively large, RT + dependencies is 80 MB and at the moment slow sending an image to Gimp.
GIMP RAW import isn't limited to darktable or RawTherapee. I have GIMP-2.9 set up with three different raw processors: darktable, RawTherapee, and PhotoFlow, and all three of these raw processors show up in "Preferences/Image Import". GIMP code provides a way to "hook" a raw processor to GIMP, to allow opening raw files directly from GIMP. But the GIMP devs didn't write the actual plug-in code for dt/RT/PF. That was done respectively by the dt/RT/PF devs. I'm guessing that the only thing keeping nufraw from showing up in GIMP's "Preferences/Image Import" is that nufraw doesn't have code that follows the same "GIMP raw plug-in" code pattern that dt/RT/PF use.
What Elle says. RAW import plug-ins must now register themselves as such, using gimp_register_file_handler_raw(). Have a look at the code in the DT and RT plug-ins and add that single line to the nufraw code. it will then show up in prefs -> image import as a choice.