[digiKam-users] Keyword (metadata) consistency between programs

[Remco Viëtor]

On mardi 28 avril 2020 23:45:41 CEST Alan H wrote:
> I was thinking that given the configuration option “use a compatible file
> name for writing sidecar files”, and digiKam creating files using the
> extensions (.on1 & .xmp) that ON1 uses, that the sidecars would be
> interchangeable. The internal structure of the files even appears to be
> similar between what digiKam creates and ON1 creates (to an end-user,
> perhaps not a developer/programmer).

> Unfortunately it seems that contradictory metadata is written. As you may
> see in the Dropbox files jpeg metadata is overwritten by raw metadata in
> what are suppose to be jpeg blocks. Or, metadata is not updated without
> applying a very unintuitive process. Raw photo metadata can therefore be
> embedded in jpeg photos.
> 
There's syntax (which XML fields are written) and semantics (what's the exact 
meaning of the contents). The syntax is declared in the namespace definitions, 
not the semantics. So if ON1 uses jpeg blocks and raw blocks in one file, 
digikam may not realise those can legitimately hold different info.

> Perhaps there could be more detailed explanation by digiKam what was meant
> by “Use a compatible file name….” since the way I thought it worked does
> not appear to be correct, or I’m not using it correctly. Or maybe ON1 has
> advanced the structure of their sidecar files beyond what digiKam has
> programmed.

 "Compatible file name for sidecar files" means basically "use this extra 
extension for XMP files". The internal structure will be the same for all 
sidecars (it's derived from XML). Available tags may differ, and on reading 
digikam should ignore tags it doesn't know about.

Remco

P.S. Referring here to files you apparently want to keep private isn't 
particularly helpful