Bug 114884

Summary: default compression rate for Jpegs looses data, should be set to 100% quality by default
Product: [Applications] digikam Reporter: S. Burmeister <sven.burmeister>
Component: Plugin-DImg-JPEGAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED NOT A BUG    
Severity: normal    
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed In: 7.6.0

Description S. Burmeister 2005-10-22 19:22:27 UTC 
Version:            (using KDE KDE 3.4.92)
Installed from:    SuSE RPMs
OS:                Linux

I think that the user should not by default loose data when editing pictures. Hence the default-value for Jpeg-quality should be 100% and not 75%.
Comment 1 caulier.gilles 2005-10-22 20:49:43 UTC 
I think this bug report isn't correct.

1 / JPEG isn't a lossLess image file format. 
2 / LossLess file format is PNG or TIFF.
3 / Jpeg compression factor to 100% isn't lossless.
4 / Jpeg is dedicaced to web publish, not image edition.

If you want more information about image file format supported in digiKam, please take a look in current handbook (0.8.0 from svn).

Regards

Gilles Caulier
Comment 2 Joern Ahrens 2005-10-22 20:55:18 UTC 
On Saturday 22 October 2005 20:49, Gilles Caulier wrote:
[bugs.kde.org quoted mail]

You're right Gilles, but this discussion comes up again and again, so why 
shouldn't we change it to a 100% default? People are satisfied and who reads 
the manual knows it better ;-)

... J
Comment 3 caulier.gilles 2005-10-22 21:05:10 UTC 
Hi Joern, 

Because 100% compression factor isn't loosless and because the file sizes will be very increased. There is a risk to have any users to report this point like a bug (:=).

Notes: 

- Look like Gimp and photoshop use 75% compression factor by default.
- Provide LoosLess Jpeg compresion in digiKam request new Jpeg codec in image editor. This is can be done when we will use DImage API instead imlib2 for example.

Gilles
Comment 4 Joern Ahrens 2005-10-22 21:09:17 UTC 
On Saturday 22 October 2005 21:05, Gilles Caulier wrote:
> Because 100% compression factor isn't loosless and because the file sizes
> will be very increased. There is a risk to have any users to report this
> point like a bug (:=).


Haha, you're right again. So here is everything said and we can close it.

... J
Comment 5 S. Burmeister 2005-10-22 21:14:16 UTC 
Or make it a wish to introduce lossless-jpeg. :)
Comment 6 caulier.gilles 2005-10-22 21:23:22 UTC 
Right. Please make a new wish in B.K.O about it.

I close this file.

Gilles