Search for Iptc4XmpExt fields in digiKam

Hi all,
I’m considering switching from my previous DAM to digiKam and I’m in the process of getting used to it.
At one point I can’t get any further at the moment.
The question is, can I filter or search for Iptc4XmpExt fields in digiKam?
In the photos that I want to migrate, for example, the location information is already written into the appropriate fields via reverse geocoding, e.g. Iptc4XmpExt.LocationCreated.City.
Likewise people are to be found in Iptc4XmpExt.PersonInImage.

After importing into digiKam, this information can be shown for a selected photo in the right sidebar under “Caption”, but I can’t find a way to filter for such an entry nor create an advanced search.

What am I missing?

Thanks in advance for any assistance.

O don’t think you are missing anything.

Digikam doesn’t give you direct access to most metadata tags, but has its own set of “image descriptors” ( “tag” is getting too many meanings here…), which can be based on multiple metadata tags. Keywords (digikam’s “tags”, caption and description are good examples of this: each can be stored in or read from several metadata tags…

I think the more technical metadata (things like whitebalance setting, exposure and F-stop) are a 1:1 correspondence with EXIF tags. Those are typically written by the camera and tend to be reasonably standardised (except for the “makernote” EXIF data…)

For anything added by the user (or user programs) the situation is more complicated (not to say “messy”): over time, several ways of adding information were developed (IPTC, XMP), e.g. IPTC has several versions,
and many programs have their own way of storing information in the metadata (cf. XMP namespaces).

The advanced search is based on a database with a fixed schema and limited in fields you can search.

One work-around is adding custom keywords to the XML sidecar files with external tools. digiKam will import these keywords and they can be searched.

I described my workflow here:

Thank you everyone for your support.

I totally agree, metadata is a can of worms. And the halfhearted attempts that some image editing programs make when introducing an image management module don’t make it any better.

I’m fine with the way digikam handles this, I just wasn’t sure if I missed something.

Fortunately, I can configure my current DAM to additionally write keywords for places, events, and people. OK, that is somehow redundant, but then I can use the data already present in the images in digiKam too.

Thanks again for your input.