GNOME Bugzilla – Bug 677668
Excessive CPU usage when using Paintbrush tool (compared with 2.6.11)
Last modified: 2012-06-10 22:49:37 UTC
I've just upgraded from 2.6.11 to 2.8.0. I've noticed that CPU usage has increased dramatically when using the paintbrush tool on the same jpg file. So much so that my cpu cannot get closes to handling it. I'm checking cpu using Windows Task Manager. I have a 2 cpu machine. On 2.8.0, when using the paintbrush, cpu maxes out quickly and painting stalls. On 2.6.11 cpu reported maxes at around 40% and painting is very smooth and fast.
It must be a bug in cairo again on windows. Try disabling the brush outline. On linux painting is MUCH faster in 2.8 than it was in 2.6 specialy for large brushes due to some significant changes.
Created attachment 216019 [details] jpeg image that paints well in 2.6 and 2.8 This image relates to bug 677668.
Created attachment 216020 [details] This file does not paint well in GIMP 2.8 This file is relatefd to bug 677668. It paints well using 2.6 but is very slow in 2.8
So this is due to the color management performance problem?
I don't know how to disable brush outline - I'm very much a GIMP novice. If someone posts instructions I'll try. However I've discovered that it seems to be image related. I've just posted 2 .jpg images. The first is a photo that I took, reduced to 640 x 480. This paints well in 2.6 and 2.8. The second is an MS Windows sample image. The original was 1024 x 768 and this painted well in 2.6 but not in 2.8. I reduced the size to 640 x 480 to see if was an image size problem. I don't think it is - the smaller image (attached) also paints well in 2.6 but not in 2.8. I'm happy to do more tests. Let me know what would be useful. Ron James
Please check if this is bug #645345.
yes, I believe it is bug 645345. The selection tool works fine on both files in 2.6. IN 2.8 the selection tool works fine on image id 216019 but is very slow on image id 216020.
Thanks for the bug report. This particular bug has already been reported into our bug tracking system, but please feel free to report any further bugs you find. *** This bug has been marked as a duplicate of bug 645345 ***
I believe the bug "depends" on the actual image file being edited. I.e. neither bug (painting not selecting) appears on my system using the attached photo ID=216019 and GIMP 2.8. However both bugs (painting and selecting) appear on my system when using the attached photo ID=216020. If you think this is relevant you may want to attach these 2 images to bug #645345 or at least ensure that this information is propagated to bug # 645345.