GNOME Bugzilla – Bug 759805
Shrinking square selection is extremely slow
Last modified: 2018-05-24 15:59:05 UTC
Hello I made a 4800x4800 px selection and shrunk it down by 1000px. This took around 5 minutes. Today's GIMP-master, quad-core i7 820QM 8GB RAM, I don't think details are needed. I understand that you're busy coding features and not concentrating on optimization yet, but please add this to the optimization TODO list once you get to that stage.
More details needed methinks. What tool or menu function used and what modes ? If you mean using the Scale Tool to re-size the image data within a selection, that operation (4800x4800 -> 3800x3800) on my i3 laptop takes roughly: 8-bit integer gamma image, cubic interpolation ....25 seconds 8-bit integer gamma image, NoHalo interpolation ...60 seconds 32-bit float gamma image, cubic interpolation .....30 seconds 32-bit float gamma image, NoHalo interpolation ....110 seconds And that's with just a single gegl thread. If that's the operation you're talking about and it really is taking 5 minutes on your i7, perhaps you've got a (very) sick i7 or a (very) sick GIMP/GEGL :)
8-bit JPEG without changing precision, 9600x4800 dimensions, the right 4800x4800 half was selected, square selection made with the "Rectangular selection" tool, Select > Shrink. commit edff1d0 which is actually from a few days ago, I can't build today's yet because of mypaint-gegl hell. Nothing to do with the "Scale Image" tool.
I just tried this on both master and 2.8, and it takes forever on both, don't know if it got faster or slower in master because I aborted both tries after a few minutes. Regardless, I don't think that shrinking by 1000px is high on the list of important optimizations, but it's clearly a pain that should be faster, or at least have a progress.
-- GitLab Migration Automatic Message -- This bug has been migrated to GNOME's GitLab instance and has been closed from further activity. You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.gnome.org/GNOME/gimp/issues/815.