[Digikam-users] certain Gimp xcf files cause showFoto to crash

[Jean-François Rabasse]

Hello,

My 5 cts comments, as I am an intensive Gimp user.
(I say user, not addict :-)


On Sat, 21 Sep 2013, Elle Stone wrote:

> My xcf files are generated by the development version of Gimp, so I
> haven't filed a bug report with digiKam as the file format itself
> might be in a state of flux.
>
> I don't know whether xcf files from Gimp 2.8 cause crashes or not.
> Has anyone experienced such crashes?

I am a bit surprised to read this, as I use Gimp 2.8 too, and I have
plenty of .xcf files in my Digikam folders. Gimp is my edition tool
and .xcf is my working format, so I usually have a xcf file plus a
Jpeg for the final image.

I don't use showFoto, but I can say Digikam works perfectly well with
my xcf files. Scanning for new images is ok, folders thumbnails views
are ok, xcf appears with their correct thunmbnail, and clicking on the
thumbnail show the image correctly. I've never experienced a crash.

Strange indeed. Should probably be a configuration problem, or diffs
in environment between Elle's configuration and mine.



On 9/20/13, HaJo Schatz <hajo at hajo.net> wrote:

> I think the solution for that should be to fix the programs so they
> can read xcf properly rather than disabling support ;)

I agree with Hajo, xcf is a useful format.



On Sat, 21 Sep 2013, Gilles Caulier wrote:

> Subject: Re: [Digikam-users] date problem
>
> Note : it's serious problem with gimp to lost metadata. I know this
> problem since many year ago.
>
> With all 3rd party components available in open-source to manage
> metadata, it's to gimp team to fix seriously this problem. After all,
> Photoshop take a care about metadata. why not Gimp ?

Gimp processes correctly Exif and IPTC metadata.
What is read from the original image is saved into the xcf file.
And when work is over and the final image is generated from Gimp,
be it a Jpeg, PNG, etc., the metadata is there in the output file.

Gimp has a broken XMP parser and looses XMP metadata upon read,
so XMP data isn't exported in Gimp output files. This exists from
the beginning.

This XMP problem has started to be treated these last two months and
the next releases of Gimp, 2.9 or 3.0, are expected to support XMP
data correctly (using libexiv2 and the GNU gexiv2 wrapper.)

Also, Gimp xcf format supports metadata (except XMP because of the
current broken parser) in read/write mode from inside Gimp, and in
read mode with some external applications.
- exiftool reads correctly metadata from xcf files, but can't write back.
- exiv2 doesn't support the format
   (error message : The file contains data of an unknown image type)

So, it's not just a Gimp related problem. Once the XMP problem will be
fixed (in the next months), the xcf support will still remain questionable.

I've no definitive idea of what should be done about that. Im my opinion,
applications specific formats like xcf should probably be considered
the same way as RAW files. I.e. « try to read, but don't touch ! »
Nothing but my opinion.
Anyway because of the broken XMP support, I work with sidecar files for
my metadata, so...

Regards,
Jean-François