Bug 97777

Summary: images pixelated after edit and save
Product: [Applications] digikam Reporter: Juergen Helmers <juergen.helmers>
Component: ImageEditor-SaveAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: caulier.gilles
Priority: NOR    
Version First Reported In: 0.7.1   
Target Milestone: ---   
Platform: Mandrake RPMs   
OS: Linux   
Latest Commit: Version Fixed/Implemented In: 7.5.0
Sentry Crash Report:

Description Juergen Helmers 2005-01-24 10:00:16 UTC 
Version:           0.7.1 (using KDE KDE 3.3.2)
Installed from:    Mandrake RPMs
Compiler:          gcc version 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)
OS:                Linux

Hi!
I run digikam 0.7.1 compiled from source on my Mandrake 10.1 system with updated kde (version 3.3.2) and have the following problem: When I edit an image (jpeg) and then save the image, the saved image becomes extremely pixelated. It's looks like a huge compression artifact combining same colors more into blocks then pixels. The pictures become completely useless.

I have compiled digikam using these dependencies:

kipi-plugins-0.1
libkipi0-0.1-2
libexif12-0.6.11-1mdk
libkexif0-0.2.1-1mdk
libgdbm3-devel-1.8.3-2mdk
libimlib2_1-devel-1.1.0-4.1.101mdk

Cheers Juergen
Comment 1 caulier.gilles 2005-01-24 11:35:40 UTC 
Witch JPEG compression level you use in 'Settings/Configure digiKam/Image Editor' pannel ?

Standard JPEG compression level is 75.

Gilles Caulier
Comment 2 Juergen Helmers 2005-01-24 11:54:47 UTC 
Hi!

That clears things up...

I had the slider all the way on the left resulting in a setting of 10. I had figured that this is the compression level (as it says left of the slider), meaning only 10% compression but it seems that it is the other way around. So if I want maximum quality I have to set this to 100%...!? That is weird especially with the png settings underneath, where usually a lower setting means better quality, so 1 == good and 9 == max compression. In all other pic apps (aka gimp or photoshop), this setting would be called "quality setting" which would refelect the fact that higher means better...

Anyways, this closes the bug in a snap, not being one after all. I would vote for a change in name for this setting, not so much because I was too dumb to get it but rather to be compliant with other apps :-)

Thanks for the help!!

Cheers Juergen
Comment 3 caulier.gilles 2005-01-24 12:30:30 UTC 
JPEG quality depend of jpeg compression ! I will update the tooltips of the JPEG Compression silder.

PNG is a lossless compression format. Only the image file size depend on the compression value (and the speed to compress/decompress the image).

I will normalize too the min. and max. compression value accordinly with the Gimp/Photoshop option.

Gilles Caulier
Comment 4 caulier.gilles 2005-01-24 16:21:34 UTC 
Fixed in CVS : 
- Slider limits for PNG compression using 1-9 like in Photoshop and gimp.
- JPEG compression ==> JPEG Quality

Gilles Caulier