[Digikam-devel] [Bug 166564] Display of *already* *created* thumbnails is slow

[Marcel Wiesweg]

------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.
         
http://bugs.kde.org/show_bug.cgi?id=166564         




------- Additional Comments From marcel.wiesweg gmx de  2008-07-17 22:20 -------
Please test if the changes above improve the situation.

To have valid tests, please remove the influence of hard disk access - use a large album (a few hundred images), scroll slowly to the bottom so that all thumbnails have once been loaded and are in Linux' disk cache. Then go up again to images that have fallen out of (our pixmap) cache.

With Callgrind, in this loading situation, 70% is spent inside libpng. Note that the code for loading pregenerated thumbnails with libpng did not change since KDE3. 8% in QImage::scaled, 20% in the event loop. This misses all time spent in X11, so drawing is the one area that may be a problem currently - and drawing speed, graphics driver problems may enter the scene here.