[Digikam-users] How to "integrate" digikam and gimp?

Arnd Baecker arnd.baecker at web.de
Sun Oct 19 08:08:44 CEST 2008

On Sun, 19 Oct 2008, gerlos wrote:

> Thank you for your answer,
> Arnd Baecker wrote:
> > On Fri, 17 Oct 2008, Gerlando wrote:
> >
> >
> >> The problem is when I open a photo with Gimp, I edit it, and save a
> >> copy: my copy is without any metadata, and I have to search it, and add
> >> manually comments, tags and stars.
> >> I'd like to find an easy way to copy metadata from the old version to
> >> the new one.
> >>
> >
> > There are a couple of issues here
> > - only recent versions of gimp load/save the exif info of images,
> >   as far as I know.
> >   (this can be easily tested outside of digikam by running
> >      exiv2 pt original.jpg
> >      gimp original.jpg
> >      # save as mod.jpg
> >      exiv2 pt mod.jpg
> >   For me exif info is kept with gimp 2.4.5
> >
> Ok, also for me exif info are kept, and I'm using Gimp 2.4.7 (with
> Mandriva 2008.1). But other metadata (IPTC?) is missing. But I can't see
> them using exiv2 0.16, even in the original image. I can only see exif
> info (maybe I misunderstand something?).

The IPTC data is shown with
  exiv2 -pi original.jpg
(see exiv2 --help for all the options ...)

> But using exiftool 7.15 I see my tags inside the "Keyword" IPTC tag and
> my ratings ("stars") as "Urgency" tag associated to the original image,
> and I can see that these tags are missing in the version modified with Gimp.
> So, if Gimp could keep these IPTC tags in the new image, this problem
> should be solved!

So you need to check with the gimp-folks, whether this is planned...

> > - If comments, tags, rating have been made within digikam
> >   and not written to the image itself, these will not be
> >   transferred to the modified image,
> >   as they are just kept in digikam's database
> Mmm... I did some experiments and my experience it's different, or I
> don't understand something in what you say.

> I configured Digikam so that it save image tags inside the IPTC
> "Keywords" tag, and so that it save also comments inside the images (I'm
> sorry I can't be more precise, since my Digikam is localized in Italian
> and I'm not sure about the correspondence between option names...).

Digikam's default is such that it does not modify files.
As you configured digikam to save the info in the image files,
it should have worked fine, but it does not because gimp
does not transfer the IPTC as you demonstrated above!

> When I look at the metadata using exiftool, I see that my comments, tags
> and ratings are saved inside the exif comment tag, the iptc keywords tag
> and in the iptc urgency tag. If I set these tags manually using exiftool
> on an new image, and I put it in a directory used by digikam, I find
> that these metadata are correctly interpreted and displayed by Digikam,
> so my new image can merge instantly to my collection, as I wanted when I
> started this thread.
> So I've seen that this way I can move my images anywhere, even not using
> digikam, without loosing informations. Really good: I've learned
> something useful...
> But why isn't Digikam behave this way as default? I think it would be
> really convenient.

Well, some people have the philosophy, that no programm
should touch their original images in any way.
Personally I therefore think this is a good default.

> >> Yes, it would be fantastic if it would be automatic, just like when I
> >> edit and save a copy using Digikam editor, but I understand that maybe
> >> it isn't easy to do! (it depends on digikam and gimp...)
> >>
> >
> > Well, I think the main problem is that a priori there is no
> > way for digikam to know under which name you will store an
> > edited file.
> > So for digikam, the file saved via gimp will appear
> > as a new file.
> > One could try to do some guessing, based on the metadata
> > (i.e. date/time of the image and some other infos).
> > This might even work fine in 99% of the cases, but
> > somehow I have the feeling that there can be situations
> > where things can get screwed up.
> >
> It wouldn't be too difficult this way? It wouldn't be sufficient if gimp
> preserved also IPTC metadata, so Digikam will look at keywords an
> urgency tags, and add the image to the database as said before?
> I think I'll ask to someone at Gimp if they're planning to add a feature
> to preserve also IPTC metadata after processing...
>  From this point of view it doesn't seem any more something to change in
> digikam, it seems something to change in gimp.

Yes, it would be great if you could ask the gimp experts!

> >  > Installing kipi-plugins I've found a submenu with some commands to
> >
> >> import metadata, but I couldn't find nothing to export it!
> >> It would be nice to have a couple of buttons, or something in the
> >> right-click menu to copy and paste metadata!
> >>
> Actually, I found that I was wrong: in the metadata tab on the right (in
> my italian version is called "Dati Aggiuntivi", hope that is the right
> translation...) there is a IPTC tab, showing these data, and clicking on
> the save button on the top of the tab is saves a binary file that seem
> to contain the right metadata (I inspected it piping the output of cat
> to strings).
> But when I go to the import iptc metadata menu provided by kipi-plugins,
> and I choose the file saved before, it gives me an error message, saying
> that it can't load data from the file I provided. so I suppose that the
> plugin is expecting a differently formatted file. Maybe I'm wrong, but
> it seem really strange to me.

Hmm, I am not familiar with this import/export stuff.
Gilles, what do you think?

> > You could simulate something like this by
> > adding a script to the "Open with" right-click menu,
> > which uses the current file, extracts the metadata
> > using exif and puts the output into the X11 buffer using
> > wxcopy/wxpaste. (Note that this is untried ...;-).
> > For a more integrated variant, using something like
> > https://bugs.kde.org/show_bug.cgi?id=88932
> > would be helpful, even though that would also not allow
> > you to get tags/comments/ratings if they are only
> > stored inside of digikams database.
> >
> Thanks, I think that I will try this solution.
> > I would suggest to file a new wish in the bug-tracker.
> >
> Done. :-)


Best, Arnd

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