Bug 444767

Summary: All face thumbnails in a picture refresh each time a face is confirmed
Product: [Applications] digikam Reporter: MarcP <iwannaberich>
Component: Maintenance-FacesAssignee: Digikam Developers <digikam-bugs-null>
Status: REPORTED ---    
Severity: minor CC: caulier.gilles, iwannaberich, metzpinguin
Priority: NOR    
Version: 8.0.0   
Target Milestone: ---   
Platform: Flatpak   
OS: Linux   
See Also: https://bugs.kde.org/show_bug.cgi?id=466412
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description MarcP 2021-11-01 11:24:08 UTC 
SUMMARY
When tagging people in the People tab, face thumbnails are generated on the fly, as they are scrolled through (bug #395241), and sometimes they take a while. Another problem related to that seems to be that every time a face is confirmed in a picture containing multiple faces, all the other face thumbnails disappear and need to regenerate again. Or maybe it is not regenerated, but just read from the database again. 

But in any case, it can take minutes until the thumbnail is visible again. I guess this is specially relevant if the pictures are stored in a network share, since tagging multiple persons in a picture can take a while (tag 1st person, wait until thumbnails are generate again, tag 2nd person, etc.), but I have personally not compared the same process when pictures are stored locally.

STEPS TO REPRODUCE
1. Scan faces in a picture with multiple people
2. Go to the People tab, and confirm the name in one of them.

OBSERVED RESULT
3. Observe how thumbnails for other faces in that picture become invisible for a while.

EXPECTED RESULT
4. Do not refresh the thumbnails for the already existing faces again.

SOFTWARE/OS VERSIONS


Linux/KDE Plasma: Digikam 7.4.0 Build date: 30/10/21 10:27 (target: Debug)
Rev.: 23194bade7c237df0385dc18781788da713e1ed4 (flatpak)
on Ubuntu 20.04 LTS
Comment 1 Maik Qualmann 2021-11-01 12:28:42 UTC 
Did you test it with disabled metadata option to clean up the database when changing?
In the current developer version, it is possible to use a local thumbnail database, you can please test it. It will take time to create the thumbnails on the fly or with the maintenance tool again. But you can also switch without problems later to the network thumbnail database.

Maik
Comment 2 Maik Qualmann 2021-11-01 12:33:43 UTC 
Otherwise yes, an event is sent to the view when writing metadata, so these faces are also reloaded in the same image. We will not be able to change that.

Maik
Comment 3 MarcP 2021-11-01 13:13:49 UTC 
I will try disabling the "Clean the metadata from the database when rescan files" for face tagging, and report back.

Where I can enable the use of a local thumbnail database? I'm using the latest flatpak nightly version, but I don't think that's the developer branch you're referring to, isn't it?
Comment 4 MarcP 2021-11-01 13:18:29 UTC 
Ok, it seems that disabling that option does not affect the behavior described in this bug. Faces still go "blank" when you tag another person in the same picture and you have to wait for the thumbnail to be generated again.
Comment 5 Maik Qualmann 2021-11-01 13:39:42 UTC 
Your Flatpak Rev. already contains the change. Go to the digiKam setup under database and select a local folder for the thumbnail database.

Maik
Comment 6 MarcP 2021-11-04 18:28:49 UTC 
I can't find that option. On Settings, Database, I only see a a menu to select the type of database, and the path for the database, nothing else.
Comment 7 Maik Qualmann 2021-11-04 18:47:04 UTC 
I thought you would use external MySQL? A SQLite DB is (should) always be local. Then it does not bring you any advantage.

Maik
Comment 8 MarcP 2021-11-04 18:51:31 UTC 
(In reply to Maik Qualmann from comment #7)
> I thought you would use external MySQL? A SQLite DB is (should) always be
> local. Then it does not bring you any advantage.
> 
> Maik

I always use a local database, on an nvme drive. The only think I store over the network are the pictures. Should I try with MySQL instead of SQLite?
Comment 9 Maik Qualmann 2021-11-04 18:53:59 UTC 
No, SQLite is fine.

Maik
Comment 10 caulier.gilles 2023-05-06 08:44:35 UTC 
MarcP,

I suppose that problem still reproducible with 8.0.0 ?

Gilles Caulier
Comment 11 MarcP 2023-05-06 10:57:47 UTC 
Yes.
Comment 12 Maik Qualmann 2023-09-03 20:14:01 UTC 
Yes, there are changes in the metadata, this causes the view to be reloaded. In principle, this can hardly be changed, since digiKam can also react to external events.

Maik