XCF issues and more

[Gilles Caulier]

Hi Carol;

As I already said previously, please report the XCF files support bug
in the KDE KImageFormats framework component which is in used of
rendering the XCF thumbnails in digiKam (and all KDE applications in
fact). The entry is very similar to your problem, and i recommend to
add a new comment to this file instead to create a new one:

https://bugs.kde.org/show_bug.cgi?id=491795

Explain well the context to reproduce, and share some XCF files if necessary.

Best regards

Gilles Caulier

Le mer. 30 juil. 2025 à 03:27, Carol <carol at kankelborg.net> a écrit :
>
>
>
> > On Jul 27, 2025, at 03:55, Gilles Caulier <caulier.gilles at gmail.com> wrote:
> >
> > Le ven. 25 juil. 2025 à 22:48, Carol <carol at kankelborg.net> a écrit :
> >>
> >>
> >>
> >>> On Jul 25, 2025, at 03:06, Gilles Caulier <caulier.gilles at gmail.com> wrote:
> >>>
> >>> Le jeu. 24 juil. 2025 à 22:29, Carol C. Kankelborg
> >>> <cckborg2 at kankelborg.net> a écrit :
> >>>>
> >>>> Hi,
> >>>>  I recently upgraded to DigiKam 8.7.0 (Build Date 6/29/25 09:49), running on Sonoma 14.7.6. I ran the maintenance tools to clean up the database and rebuild thumbnails & fingerprints.
> >>>>
> >>>> Before upgrading, there were a bunch of .xcf files that were grouped together under 100% similarity but were clearly very different from each other. After upgrading, these same files are grouped together in similarity, but the thumbnails and preview in Digikam is blank (all white). This doesn’t affect all of my .xcf files. As an example, I have one file I edited with Gimp from a scan from 11/3/22 that looks blank and another from 11/4/22 that looks fine. The blank one looks fine when I open it in GIMP.
> >>>>
> >>>> Is this a bug I should report or is there some setting that is throwing DigiKam off?
> >>>
> >>> Hi Carol,
> >>>
> >>> The XCF support is delegate to a KDE framework component named
> >>> KImageFormats. There is no specific code in digiKam to handle XCF
> >>> files.
> >>>
> >>> https://invent.kde.org/frameworks/kimageformats
> >>>
> >>> XCF support have been problematic in the pass. Even if The Gimp is
> >>> open Source, the file format change in time and support become broken
> >>> while a period a time. The Gimp in the past provided a library to
> >>> handle the file format. This library have been dropped and non
> >>> supported since few years. So the people in charge to develop the XCF
> >>> thumbnailer code fight against the complexity.
> >>>
> >>> As you use MacOS, the KDE framworks is a little bits outdated in the
> >>> 8.7.0 release. I will up-to-date this one in the current 8.8.0
> >>> pre-release, probably this week end. Like this you will able to test
> >>> is the new KImageFormats component fix your XCF problem.
> >>>
> >>>>
> >>>> I sent the above question with a sample .xcf file that was too big so it is awaiting moderator approval. I decided to scale down the image in GIMP and import it into DigiKam to see if it still had the problem, so I could resend my question within the size limits. I encoungered more bugs.
> >>>
> >>> If bug must be reported about XCF, no need to do it in the digiKam
> >>> space. Use the KImageFormats component instead in bugzilla:
> >>>
> >>> https://bugs.kde.org/buglist.cgi?bug_status=UNCONFIRMED&bug_status=CONFIRMED&bug_status=ASSIGNED&bug_status=REOPENED&classification=Frameworks%20and%20Libraries&list_id=3209147&product=frameworks-kimageformats&query_format=advanced
> >>>
> >>> ... And as you can see there is 3 current reports about XCF...
> >>>
> >>
> >> I am disappointed to hear that support for XCF has been such a problem for DigiKam. I was looking forward to having all my image files in one place. Hopefully the updates in 8.8.0 will be an improvement.
> >>
> >> Will I be able to go back to 8.7.0 after testing out 8.8.0 or will I have to stay with 8.8.0 once I run it? Either way, I will back up my database before testing out XCF on 8.8.0.
> >
> >
> > The KDE frameworks in now up-to-date in next 8.8.0:
> >
> > https://imgur.com/a/ZrDyIuR
> >
> > If the fix for XCF has been introduced, this must be in the KDE
> > Framework KImageFormats. Please test with the current digiKam 8.8.0
> > PKG installer here :
> >
> > https://files.kde.org/digikam/
> >
>
> Gilles,
>
> I downloaded the latest 8.8.0 (dated July 28). The XCF files that showed as white thumbnails and previews, created in GIMP2, still show all white. I opened one with GIMP3 in place, saved it, and scanned for new items. That file now shows as a generic picture icon labeled XCF as a thumbnail and blank in preview. That is not ideal, but at least it is handled more gracefully than just a blank thumbnail and is consistent with GIMP3 not being supported.
>
> If I understand correctly, GIMP 2 formats should be supported — and most of my GIMP2 XCF files do seem to display properly. There are just a handful that display incorrectly (10 out of 53).
>
> Should I report this as a bug? If so, with DigiKam or with GIMP?
>
> Thanks,
> Carol
>
>
>