gwenview rotate causes jpg quality loss

[oliver.w]

VERSION INFORMATION:
=============================
Description: Ubuntu 8.10
Release: 8.10

Qt: 4.4.3
KDE: 4.1.3 (KDE 4.1.3)
Gwenview: 2.1.3

gwenview:
  Installiert: 4:4.1.3-0ubuntu1~intrepid1
  Kandidat: 4:4.1.3-0ubuntu1~intrepid1
  Versions-Tabelle:
 *** 4:4.1.3-0ubuntu1~intrepid1 0
        500 http://at.archive.ubuntu.com intrepid-updates/main Packages
        500 http://at.archive.ubuntu.com intrepid-backports/main Packages
        100 /var/lib/dpkg/status
     4:4.1.2-0ubuntu3 0
        500 http://at.archive.ubuntu.com intrepid/main Packages

Bug Description
=============================
When some pictures are rotated with gwenview, the quality of the new picture is changing. I have seen so far the following behaviours and cannot explain what rules it follows.
So far it seams like pictures which are taken with my new camera are rotating correctly. Other pictures taken with my old camera loose quality:

- rotating especially older jpg pictures result mainly in:
     JPG Quality of 75 %
     Original (non rotated ones): 95-97%

- some pictures even result after rotating:
     JPG Quality of 100%
     Original (non rotated ones): 95-97%

I could not figure out which general parameter of the pictures result in the above behaviour.
I have attached 1 picture - IMGP1008.JPG.
Rotating of this pictures causes a quality loss to 75%.
I can reproduce this 100% on my machine.

Sorry, the pic is big. But when I resize it through gimp first, the quality loss will not happen anymore with gwenview.

I hope this helps to solve the bug. It is a bit anoying.... as not clear when it happens. There is also no feedback from gwenview when quality is changed!

[Hervé Fache (rvfh)]

NO!

This is not a duplicate: mine was about EXIF info lost, this one is about
quality degradation (please re-read the descriptions).

Even if the solution was the same for both (EXIV lib broken), they would
still NOT be the same bug.

[Jonathan Thomas (echidnaman)]

The quality setting is stored in the EXIF data, so when the EXIF data is lost the image is saved at a lower quality. (The default, 75%)

[Hervé Fache (rvfh)]

I stand corrected.

[oliver.w (kubuntu-freedom-net)]

Where is the information lost in this picture?

Which is the Exif quality parameter?

I find only the Quality with:

"identify -verbose xxx.jpg"

And it gives:
Quality: 94

So why this information is lost?
Where should it be?

[oliver.w (kubuntu-freedom-net)]

Dear Jonathan,

any info on my questions already? I still do not understand what is going wrong here. The info is available in the picture. If I know what the issue is, I can change the pics accordingly.

Further it would be good if gwenview gives a warning about the quality when it sets to "default". Or when it is possible to change the default quality by the user.

Thanks in advance.
Oliver

[Jarl (jarl-dk)]

This is not a duplicate of bug #286858. Cause as of Karmic Koala, there is no longer any loss of exif information. However Gwenview still does a lossy transformation when rotating with image quality loss as a result.

I therefore want someone with previleges to remove the duplicate status. Basically it is unfair (in launchpad) that someone (arbitrary) can mark a bug duplicate without acceptance of the bug reporter (in this case olive.w).

Jarl

[Jarl (jarl-dk)]

I realised with help from #kubuntu that I could unmark the duplicate myself. And since oliver.w (the reporter) and now also me does not consider this bug a duplicate, I have unmarked it as such.

[Flames_in_Paradise (ellisistfroh-deactivatedaccount)]

Thank you for reporting this bug to Ubuntu. Intrepid Ibex reached EOL on April 30, 2010.
See this document for currently supported Ubuntu releases:

https://wiki.ubuntu.com/Releases

Please upgrade to the latest version and re-test. If the bug is still reproducible,
increase the verbosity of the steps to recreate it so we can try again.

Do feel free to report any other bugs you may find.

[Launchpad Janitor (janitor)]

[Expired for gwenview (Ubuntu) because there has been no activity for 60 days.]