[Digikam-users] Templates: ITPC subject code

[Jean-François Rabasse]

Hello Jürgen,

On Thu, 28 Mar 2013, H. Jürgen Karbach wrote:

> I have been studied all information, I could get about
> this issue. Including the webpage you adviced.
> Unfortunately I supposed what you affirmed. There is no
> further content (with interrest for amateur
> photographers). But as a confirmed optimist I hoped for
> the opposite.
> 
> I also agree, its not usable for amateur photographers
> like us.

This is the major inconvenient with vocabularies.
All compilations target a professional area. IPTC was
designed for press agencies photo reporters and would be of
no use for, e.g., medical imagery databases or even photo
hobbyists centers of interest.

Someone may be fond of birds photography and will wish
dozens of tags referring to birds names and families.
And other users will want some other tags and when possible
extensible tags sets. (I am personally fond of architecture
and have in my tags several architectural styles
definitions. Last summer, I was in Austria, Vienna,
and needed to increase my vocabulary with entries such as
Jugendstil or Biedermeier, I hadn't yet.)

> I'm using the tags for categorising my pictures.
> But having a controlled (tag)-vokabulary would be great.

I'd recommend you prefer a managed vocabulary, rather than a
controlled vocabulary. Managed vocabulary is more personal
and can be extensible according to your needs (cf. supra).
Controlled vocabulary is a registered fixed standard and
the rule is « use it or forget it ».

But true, vocabularies are great features and allow easy
classement and reorganization. Access to tags can be done
via numeric keys as in IPTC or more readable text keys
(aliases). Also, a keyed vocabulary can, if needed,
permit languages translation on a per key basis with textual
meaning in English, German, French, etc.

> A catalog like
> http://www.coolcolours.ch/coolcolours-en.php?A=Software
> with more than 22.000 english and german terms would be a
> good starting point. ; )

Maybe... But 22000 is huge and if it increases your chances
to find the exact tag you need at a moment, it doesn't
guarantee you'll always find everything you need, depending
of your personal images and you personal interests.
Most photo hobbyists don't use that much tags.

> But how to get it in digiKam? I guess digiKam knows only
> tags that are assigned to one of the pictures in database.

Yes. But Digikam can create new tags « on the fly » when you
read metadata from images.
With a bit of scripting work and command line tools,
it's very easy to tag images from command line, e.g. in a
subdirectory :

     exiftool -xmp:TagsList+=Location/France/Paris *.JPG

then, in Digikam, select images and re-read metadata.
Tagging from command line or from inside Digikam is only a
matter of taste.

It's also possible to « read » a vocabulary tags file and
set all of them to a dummy image. Reading metadata from that
image will create all tags. I happened to do such thing but
with a limited number of tags, several tens. Not 22000 : -)

Regards,
Jean-François