Bug 184312

Summary: images are scaled using FastTransform instead of SmoothTransform
Product: [Applications] digikam Reporter: Matthias Welwarsky <matze>
Component: Plugin-WebService-FlickrAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: lure
Priority: NOR    
Version: 5.6.0   
Target Milestone: ---   
Platform: Ubuntu   
OS: Unspecified   
Latest Commit: Version Fixed In: 0.2.0
Attachments: patch to use QImage.scaled with SmoothTransform mode

Description Matthias Welwarsky 2009-02-14 14:51:41 UTC 
Version:            (using KDE 4.2.0)
Installed from:    Ubuntu Packages

When downscaling images before upload to flickr, QImage.scale() is used with default transformation mode, FastTransform. This creates ugly artifacts in downscaled images due to pixel aliasing effects. SmoothTransform should be used instead.
Comment 1 Matthias Welwarsky 2009-02-14 14:55:48 UTC 
Created attachment 31293 [details]
patch to use QImage.scaled with SmoothTransform mode

I propose the attached patch to fix the bug
Comment 2 caulier.gilles 2009-02-16 08:07:20 UTC 
Luka,

This patch is true for flickr. Perhaps it's also right with others plugins as PicasaWeb, FaceBook, Smug, etc... Can you take a look ? Thanks in advance...

Gilles
Comment 3 Luka Renko 2009-02-16 09:44:51 UTC 
SVN commit 926795 by lure:

Use Qt::SmoothTransform when image is resized. This is fixed for Calendar,
Advanced Slideshow, GalleryExport, FlashExport, FlickrExport, Facebook and 
SmugMug plugins.

Thanks to Matthias Welwarsky for noticing this and proposing patch.

BUG: 184312


 M  +10 -0     NEWS  
 M  +1 -1      advancedslideshow/imageloadthread.cpp  
 M  +1 -1      advancedslideshow/slideshowloader.cpp  
 M  +1 -1      calendar/calpainter.cpp  
 M  +2 -1      facebook/fbwindow.cpp  
 M  +2 -1      flickrexport/flickrtalker.cpp  
 M  +2 -1      galleryexport/gallerytalker.cpp  
 M  +2 -1      simpleviewerexport/simpleviewerexport.cpp  
 M  +2 -1      smug/smugwindow.cpp  


WebSVN link: http://websvn.kde.org/?view=rev&revision=926795