Due to a database corruption, some photo's were not displayed anymore. The only way (known till this date) was to recreate the database. For a lot of information / tags that is fine, as the data is stored in the database as well as in the photo files. Recreating the database from the data in the photofiles takes some time, but after that most information is back. Most as the facetag information is missing. Like most other tag information, store the facetag information in the photo file, please. When this can be accomplished it is very, very, very valuable when the database must be recreated from scratch.
In the configuration go to the metadata section and behavior tab, where you can choose which information is written to image files. One of these is face tags including face areas.
That's wunderful! Where is more information about this? H ow should the user know, that this setting exist? PS: the user should just browse the settings tab is a unexpected answer, but not the one I'm looking for. Why is it not enabled by default? What about the facetags that I already populated, how can I get those written to the photo files? Is that taken care of automatically when the setting is enabled? How can I verify that the facetag has been written to the photo files for the photos that I already face tagged?
How you should know? Well besides what you mentioned we have a manual - not sure what else you would expect. No, it is not done automatically. There is the maintenance job "Sync Metadata and Database" where you can choose "From database to image metadata" to do exactly what it says. Just be sure this is what you want, because it will overwrite all image metadata with database metadata. For verification you can for example use exiftool or exiv2 command line tools.
Thanks for the feedback. Where is it in the manual? I did not found it (just searched for it). > How you should know? > Well besides what you mentioned we have a manual - not sure what else you would expect. Propose the setting before creating the database? Why is it not enabled by default? For archive purpose I put the following information here: I found the data that is written to the photo file. Region Name : Pers 1, Pers 2, Pers 3, Pers 4, Pers 5 Region Type : Face, Face, Face, Face, Face Region Area X : 0.58125, 0.771875, 0.865625, 0.191875, 0.26625 Region Area Y : 0.429167, 0.3175, 0.3225, 0.325, 0.628333 Region Area W : 0.09, 0.06875, 0.07875, 0.09125, 0.165 Region Area H : 0.151667, 0.111667, 0.138333, 0.143333, 0.276667 Region Area Unit : normalized, normalized, normalized, normalized, normalized Region Rectangle : 0.53625, 0.353333, 0.09, 0.151667, 0.7375, 0.261667, 0.06875, 0.111667, 0.82625, 0.253333, 0.07875, 0.138333, 0.14625, 0.253333, 0.09125, 0.143333, 0.18375, 0.49, 0.165, 0.276667 Region Person Display Name : Pers 1, Pers 2, Pers 3, Pers 4, Pers 5 The data was not available, after I enabled the 'write face tag to photo file'. It was only available for the photo files after I made a dummy face tag update in the particular photo? The face tag information was also written to the photo file, with the function "write metadata to photo" (menu option: item -> "write metadata to photo"). Is there a possibility to automatically write only the face tag data to the photo files that were tagged before enabling "write facetag to photo file"? Is there a query possible to looks up which photo have face tags, and activate ""write metadata to photo" (via a dbus command)? (would that make sense)?
writting metadata in files is not enabled because by default files must be untouched. This is a legacy of users wishes. digiKam exist since 2001 and the rules have been forged year by year. this have been voted by users in bugzilla. Documentation : https://docs.kde.org/trunk5/en/extragear-graphics/digikam/using-setup.html#using-setup-metadata
Thanks.