Bug 503561

Summary:	'Background face recognition scan' feature modifies thousands of files during scan
Product:	[Applications] digikam	Reporter:	MarcP <iwannaberich>
Component:	Faces-Workflow	Assignee:	Digikam Developers <digikam-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	caulier.gilles, iwannaberich, metzpinguin, michael_miller
Priority:	NOR
Version First Reported In:	8.7.0
Target Milestone:	---
Platform:	Microsoft Windows
OS:	Microsoft Windows
Latest Commit:		Version Fixed/Implemented In:	8.7.0
Sentry Crash Report:

Description MarcP 2025-04-30 02:58:02 UTC

SUMMARY
Hi, I already mentioned this bug in comment 35 of of Bug #502219, but I thought of opening a proper bug report in case you want to have a look.

I've been testing the newest daily builds, and I noticed that when I had the "Background face recognition scan" feature enabled, whenever it runs a scan, it modifies tens of thousands of pictures on its own. I'm not sure exactly what changes on these pictures, though, as no apparent changes to the files are done.

I sync my pictures with a NAS across the network, and every time the background face recognition scan is triggered, I can see it synchronizes tens of GB of pictures. Interestingly enough, that does not happen during the initial face scan when you first open Digikam.

Today I tried in a separate user profile with a different set of files, and I could see how more than 15000 photos have been modified without me having made any change to the files. (that user's library has around 200 000 files)

I'm not sure, but I believe files are also modified when you reject a face suggestion.

Let me know if you want me to provide more information to troubleshoot it.

STEPS TO REPRODUCE
1. Start digikam with the 'Background face recognition scan' enabled.
2. Wait until that background scan is triggered (e.g. by manually confirming a face suggestion).
3. Check last modification date for files in the library.

OBSERVED RESULT
- Observe how the last modification date of many pictures has been changed on its own.

EXPECTED RESULT
- Nothing should be modified on a picture unless I explicitly make a change (like tagging a face or a keyword).

SOFTWARE/OS VERSIONS
Windows: Windows 10 22H2
digiKam-8.7.0-20250403T061347-Qt6-Win64.exe

Comment 1 Michael Miller 2025-04-30 13:50:02 UTC

Git commit 37a9941380391ac74d19780f01a6474a448c69c9 by Michael Miller.
Committed on 30/04/2025 at 13:49.
Pushed by michmill into branch 'master'.

fix unnecessary writing to metadata

M  +20   -1    core/utilities/facemanagement/pipelines/edit/facepipelineedit.cpp
M  +8    -8    core/utilities/facemanagement/pipelines/recognize/facepipelinerecognize.cpp

https://invent.kde.org/graphics/digikam/-/commit/37a9941380391ac74d19780f01a6474a448c69c9

Comment 2 Michael Miller 2025-04-30 14:20:20 UTC

Git commit d7176fb789b18324635a5a2b0c51640cb5e768e8 by Michael Miller.
Committed on 30/04/2025 at 14:14.
Pushed by michmill into branch 'master'.

add extra check before writing metadata

M  +2    -2    core/utilities/facemanagement/pipelines/edit/facepipelineedit.cpp

https://invent.kde.org/graphics/digikam/-/commit/d7176fb789b18324635a5a2b0c51640cb5e768e8

Comment 3 MarcP 2025-05-04 04:51:14 UTC

Hi, I've been testing the latest build for a couple of day now, and I believe the issue is gone. Thanks so much!

Comment 4 Maik Qualmann 2025-05-04 06:33:01 UTC

Git commit f20f57ca43747346a16ad711a2b7c0f1e82cadb2 by Maik Qualmann.
Committed on 04/05/2025 at 06:32.
Pushed by mqualmann into branch 'master'.

check if it is a person system tag

M  +7    -8    core/utilities/facemanagement/database/faceutils.cpp
M  +1    -20   core/utilities/facemanagement/pipelines/edit/facepipelineedit.cpp

https://invent.kde.org/graphics/digikam/-/commit/f20f57ca43747346a16ad711a2b7c0f1e82cadb2