Bug 412339

Summary: Bug report "Gimp 2.10 XCF serious issue"
Product: [Applications] digikam Reporter: maderios <leoutation>
Component: Thumbs-ImageAssignee: Digikam Developers <digikam-bugs-null>
Severity: grave CC: caulier.gilles
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: Other   
OS: All   
Latest Commit: Version Fixed In: 7.0.0

Description maderios 2019-09-25 20:32:16 UTC
I posted a bug report here to Gimp Team about Gimp 2.10 XCF support

This is a copy:

GIMP version: 2.10.12
Operating System: Arch Linux and all others
Is the issue reproducible? : Always
The facts: at this time, Gimp 2.10 XCF files can be only loaded by Gimp (to be written by another application is not the subject here)
Except Gimp 2.10, none application is able to display Gimp 2.10 XCF multi-layers thumbnails.
Digikam, Gthumb, Nautilus, Thunar, Pcmanfm, Gwenview, Geeqie, etc, none of them can display XCF thumbnails
It has changed since 2.9 version. Before, other graphic applications could display <= 2.8 Gimp version XCF thumbnails.
Why this changing behaviour? It's a big problem for users and others apps developers.
This issue doesn't come from others softwares developers incompetence.
It comes from the fact that Gimp 2.10 code cannot be used inside other graphic softwares.
I imagine they could, in an other world, do a kind of "reverse engineering" but that would be a strange thing in a Free Software / Open Source world.
Personally, I use Gimp and Digikam. As i explain above, since 2.9 Gimp version, I can't see XCF thumbnails in Digikam.
I have to convert Gimp 2.10 XCF files to proprietary Adobe format, .psd, to see them. It may sound strange in the Linux world but, sadly, it's the reality....
Gimp is an extraordinary, irreplaceable software but, I regret to announce here that Gimp 2.10 XCF format looks like a closed format. On paper, the code is open but, in facts, it is unusable in other projects, just like a closed code.
All open source file formats offer a library to handle the data inside. Why not Gimp ?
Comment 1 Christoph Feck 2019-09-25 20:37:56 UTC
The changes were needed to support the new features in GIMP. The XCF format was never designed as an exchange format, but only as an internal format for the GIMP application. Applications need to be changed to support format changes; there is, for example, no official library that applications could use.

*** This bug has been marked as a duplicate of bug 360821 ***
Comment 2 maderios 2019-09-25 20:45:46 UTC
@ Christoph Feck from comment #1
> The changes were needed to support the new features in GIMP. The XCF format
> was never designed as an exchange format, but only as an internal format for
> the GIMP application
Never an exchange format? It's not true: up to 2.8 Gimp version, XCF format could be supported in other applications, including Digikam.
Comment 3 Christoph Feck 2019-09-25 20:58:32 UTC
The 2.8 support didn't come magically. The XCF loader had to be written by someone first.
Comment 4 caulier.gilles 2020-05-09 12:35:29 UTC
Git commit d9a57550ee4d08f1ab612723b315348af9bab9da by Gilles Caulier.
Committed on 09/05/2020 at 12:31.
Pushed by cgilles into branch 'master'.

Switch all digiKam bundles to last 5.70 which now support new Gimp XCF file format.
See KF5 release announcement : https://kde.org/announcements/kde-frameworks-5.70.0.php
"KImageFormats: Add support for modern Gimp images/XCF files"
This will permit to digiKam and Showfoto to show XCF thumbnail and load preview/full image (read only)
Related: bug 309465, bug 186641, bug 224697, bug 250003, bug 339152, bug 368444

M  +3    -3    project/bundles/3rdparty/ext_kf5_frameworks/CMakeLists.txt