[digiKam-users] Reverse geotagging and Location fields reported by exiftool

[Dougie Nisbet]

I used to use geosetter ( https://geosetter.de/en/main-en/ ) for
geotagging photos before I moved to digikam for photo management. I
found the Geolocation and Reverse Geocoding a bit confusing to begin
with but now I've got the hang of it I find it great to have it all in
one place in a single program.

I've noticed that geosetter sets the Location fields in the exif data,
but as far as I'm aware digikam does not do this. I use a 'Places' tag
hierarchy in digikam for my location data and it works fine. I have
'Write tags to XMP ticked'.

 From what I've read I appreciate that exif data is a bit of a minefield
and I don't really understand the subtle differences between IPTC XMP
and EXIF fields. Furthermore, this isn't a big problem for me I just
want to make sure that I haven't missed a setting somewhere that writes
the data into the Location fields.

For example, I'm used to typing commands such as

exiftool -City -Country -State <filename>

but this has no effect on digikam geotagged photos as the information is
stored in the tag hierarchy. I usually end up typing something like

exiftool <filename> | grep Places

or

exiftool -TagsList <filename>

which gives the whole location tree and more detail but is not as easily
readable.

It's not hugely important to me as the information I want is in the file
but I just wanted to check that I haven't missed something.

Debian Buster / Digikam version 7.1 ( digikam-7.1.0-x86-64.appimage )

Dougie

[woenx]

This may be a stupid question, but when you change the metadata using
exiftool, do you re-read the metadata in digikam?



--
Sent from: http://digikam.1695700.n4.nabble.com/digikam-users-f1735189.html

[Dougie Nisbet]

On 22/11/2020 20:55, woenx wrote:
> This may be a stupid question, but when you change the metadata using
> exiftool, do you re-read the metadata in digikam?

Yes, although it's mostly outside of digikam I'm interested in reading
the information. I use exiftool to get the information from the image
file and use it with convert to overlay onto the image.

In digikam I have Settings / Configure digikam / Metadata / Write this
information to the Metadata all checked except Face Tags,

and 'Rescan file when files are modified' is checked.

Under Settings / Configure digikam / Metadata /Views / IPTC viewer I
have all location related fields checked. This seems necessary to enable
display of the field titles under Metadata / IPTC in the main photo view
windows. However all country field names are greyed out and show as
'Unavailable'.

I'm finding it an interesting distraction because the reverse geocoding
that I do in digikam, usually using OpenStreetMap, sometimes finds
slightly different interpretations of locations to the ones that I found
using geosetter. I haven't dug into this much but I don't mind having
this redundancy as I use the exif data in photos for searching and it
means I'm more likely to get a match when searching on a location.

Dougie

[Dougie Nisbet]

On 23/11/2020 10:38, Dougie Nisbet wrote:
> I use exiftool to get the information from the image file and use it
> with convert to overlay onto the image.

That's not very clear. I mean outside of digikam I create a copy of the
image with some exif information overlayed that I use in a slideshow. I
don't copy it back into the digikam database.

Dougie

[Remco Viëtor]

On dimanche 22 novembre 2020 12:13:32 CET Dougie Nisbet wrote:

> I used to use geosetter ( https://geosetter.de/en/main-en/ ) for
> geotagging photos before I moved to digikam for photo management. I
> found the Geolocation and Reverse Geocoding a bit confusing to begin
> with but now I've got the hang of it I find it great to have it all in
> one place in a single program.
>
> I've noticed that geosetter sets the Location fields in the exif data,
> but as far as I'm aware digikam does not do this. I use a 'Places' tag
> hierarchy in digikam for my location data and it works fine. I have
> 'Write tags to XMP ticked'.
>
>  From what I've read I appreciate that exif data is a bit of a minefield
> and I don't really understand the subtle differences between IPTC XMP
> and EXIF fields. Furthermore, this isn't a big problem for me I just
> want to make sure that I haven't missed a setting somewhere that writes
> the data into the Location fields.

According to the online manual, reverse geolocation results are (only) written
in the tag tree, not to specific IPTC fields. Might be an interesting feature
request?

If your tag tree is consistent, it might be possible to update the sidecars
through a script using Exiftool (then reread metadata through digikam).
Sidecars only use XMP formatted metadata, IPTC fields are included through the
proper namespace.

Remco

[Dougie Nisbet]

On 23/11/2020 11:42, Remco Viëtor wrote:
> If your tag tree is consistent, it might be possible to update the sidecars
> through a script using Exiftool (then reread metadata through digikam).
> Sidecars only use XMP formatted metadata, IPTC fields are included through the
> proper namespace.

What I've found most distracting and interesting is that I'm beginning
to appreciate that the reverse geocoding can return different
information depending on how things are configured. Normally I use
OpenStreetMap in digikam, and I've noticed that geosetter is set up to
use geonames.org. I see now that I can select geonames in digikam too,
and I get slightly different results, although with less detail than
geosetter.

Now that I realise that digikam is using a tag tree for Places I'm quite
happy with that. I'm more curious that over the years some of my photos
have acquired some more quirky and interesting location names for
districts and villages when I've processed them with geosetter.

It probably isn't an either/or since I always write exif data to the
file. So if I do use another program, such as geosetter, and it writes
to IPTC fields, it will not conflict with digikam.

Dougie