Bug 233896

Summary:	Very poor quality low-pass filters (poor resampling/thumbnails quality)
Product:	[Applications] gwenview	Reporter:	Michał <mcv>
Component:	general	Assignee:	Gwenview Bugs <gwenview-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	aspotashev, benni, nate
Priority:	NOR
Version First Reported In:	2.9.4
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Test image KDE 3 (left) and KDE 4 (right) Gwenviews compared. Actual zoomed image in the center.

Description Michał 2010-04-09 23:52:19 UTC

Version:           2.4.2 (from KDE 4.4.2) (using KDE 4.4.2)
OS:                Linux
Installed from:    Archlinux Packages

Compared to Gwenview from KDE 3.5, version 4 has very poor resampling quality, even poorer than Gwenview 3.5 had on "lowest quality" setting. This applies not only to thumbnails, but also for normal full-screen rendering. I attached simple test image and screenshot showing Gwenview from KDE 3.5 and from KDE 4.4.

Expected behaviour is to have smooth gray image. Current Gwenview displays visible aliasing or event plain white pages (please use test file to check how Gwenview from KDE 3.5 and 4 behaves on different zoom levels).

Comment 1 Michał 2010-04-09 23:52:50 UTC

Created attachment 42634 [details]
Test image

Comment 2 Michał 2010-04-09 23:53:34 UTC

Created attachment 42635 [details]
KDE 3 (left) and KDE 4 (right) Gwenviews compared. Actual zoomed image in the center.

Comment 3 Alexander Potashev 2014-10-29 13:27:57 UTC

I confirm this on Gwenview "4.14.0 pre" with KDELibs 4.14.1 on Fedora 20.

Comment 4 Nate Graham 2017-11-10 17:17:20 UTC

Seems fixed in Gwenview 16.x and later.

Comment 5 Michał 2017-11-10 18:38:02 UTC

Indeed. Doesn't take gamma into account, but most viewer's don't and that's a minor issue.

Comment 6 Nate Graham 2017-11-10 18:39:08 UTC

Yes, and the Gamma issue is tracked with https://bugs.kde.org/show_bug.cgi?id=349067

Comment 7 Christoph Feck 2017-11-15 22:54:35 UTC

Bug 349067 talks about gamma values stored in the file, while the reporter meant http://www.ericbrasseur.org/gamma.html