[Digikam-users] Re: metadata menu and configure options

[Marcel Wiesweg]

> I have some questions about image metadata, digikam options, and
> information in the database.
> 
> 1. What controls what metadata gets written to the database  during
> image import?

Any metadata for which we have a field in the database will be read.
Regard the database as a cache in that respect.

> 
> 2. What affect (if any) does changes in Menu/Settings/Configure
> digiKam/Metadata have on what metadata goes into the database?

This for writing to a file only

> Is all
> the information displayed in the Metadata left side panel also in the
> database? Or just some of it?

The Metadata tab reads from the file only. The summary properties tab e.g. is 
fed from the db.

> 
> 3. Under Menu/Album there are two options: "Write Metadata to Images"
> and "Reread Metadata from Images". I know those sound
> self-explanatory, but what really happens? 

Reread -> Full rescan as if the file was scanned for the first time
Write -> Write from db to file, according to options

> When might one want (or not
> want) to use either of these alternatives? Is it safe to assume that
> writing metadata to a raw file is still not advised, even if possible
> (putting dng aside - I don't use dng)?

Will depend on the individual raw file type

> I'm doing a little tag-pruning,
> so would it be wise to write the updated tags back to the jpegs? 

Yes. Doing this automatically is a TODO

> How
> about tiff? png? ppm? Is there a list somewhere of supported file
> formats?

Jpg, Tiff Png have of course first-class support. Dont know if PPM supports 
metadata. We use libexiv2: www.exiv2.org there'll be a list