Bug 460482

Summary: Repeated crashes when working in Faces view while face recognition is running in the background
Product: [Applications] digikam Reporter: Jens <jens-bugs.kde.org>
Component: Faces-WorkflowAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED FIXED    
Severity: crash CC: caulier.gilles, metzpinguin
Priority: NOR    
Version First Reported In: 7.9.0   
Target Milestone: ---   
Platform: Appimage   
OS: Linux   
Latest Commit: Version Fixed/Implemented In: 8.0.0
Sentry Crash Report:

Description Jens 2022-10-15 12:33:05 UTC 
SUMMARY -> $SUBJECT

I have a faces database where - for some reason - a lot of face rectangles are bad. Some are shifted, some did not survive rotating the image and some are even outside the image (because of cropping).
My workflow to correct this is:

STEPS TO REPRODUCE
1. In faces view, select one person
2. Inside this view, repeatedly select some images, right-click "Detect faces" (to find the correct location of faces on this photo) and then immediately with the same selection click on the red (X) icon to delete *this* face region (because it's bad).
3. While face detection is running, repeat this to queue more detection.

OBSERVED RESULT
Eventually, after 5-10 minutes, Digikam will crash. This is the console output:

unknown: RST4  ( 3 )
unknown: RST5  ( 3 )
unknown: RST6  ( 3 )
unknown: RST7  ( 3 )
unknown: RST0  ( 3 )
unknown: RST1  ( 3 )
unknown: RST2  ( 3 )
unknown: RST3  ( 3 )
unknown: RST4  ( 3 )
unknown: RST5  ( 3 )
unknown: RST6  ( 3 )
unknown: RST7  ( 3 )
unknown: RST0  ( 3 )
unknown: RST1  ( 3 )
unknown: RST2  ( 3 )
unknown: RST3  ( 3 )
unknown: RST4  ( 3 )
unknown: RST5  ( 3 )
unknown: RST6  ( 3 )
unknown: RST7  ( 3 )
unknown: RST0  ( 3 )
unknown: RST1  ( 3 )
unknown: RST2  ( 3 )
unknown: RST3  ( 3 )
unknown: RST4  ( 3 )
unknown: RST5  ( 3 )
unknown: RST6  ( 3 )
unknown: RST7  ( 3 )
unknown: RST0  ( 3 )
unknown: RST1  ( 3 )
unknown: RST2  ( 3 )
unknown: RST3  ( 3 )
unknown: RST4  ( 3 )
unknown: RST5  ( 3 )
unknown: RST6  ( 3 )
unknown: RST7  ( 3 )
unknown: RST0  ( 3 )
unknown: RST1  ( 3 )
unknown: RST2  ( 3 )
unknown: RST3  ( 3 )
unknown: RST4  ( 3 )
unknown: RST5  ( 3 )
unknown: RST6  ( 3 )
unknown: RST7  ( 3 )
unknown: RST0  ( 3 )
unknown: RST1  ( 3 )
unknown: RST2  ( 3 )
unknown: RST3  ( 3 )
unknown: RST4  ( 3 )
unknown: RST5  ( 3 )
unknown: RST6  ( 3 )
unknown: RST7  ( 3 )
Digikam::DMetadata::getIccProfile: Exif color-space tag is sRGB. Using default sRGB ICC profile.
unknown: End Of Image  ( 1 )
Digikam::DNNFaceExtractor::getFaceEmbedding: Finish computing face embedding in  544  ms
Beendet

Unfortunately, running this with debug symbols enabled doesn't crash, even after 30 minutes of usage - possibly because of Bug 460464 in the current -debug appimage. So I cannot present a backtrace.

EXPECTED RESULT
No crash. Consecutively adding (queuing) images to a running face detection process should be handled by Digikam just as if all images are added at once.

SOFTWARE/OS VERSIONS: KDE Neon 20.04 with Digikam 64bit appimage 2022-10-12 (with and without debug).
Comment 1 Maik Qualmann 2022-10-15 13:09:31 UTC 
You can't have "Detect Faces" or "Scan for Faces" in the current digiKam-7.9.0 AppImage in the context menu, only "Recognize Faces"

Maik
Comment 2 Maik Qualmann 2022-10-15 13:13:22 UTC 
In addition, they cannot correct face rectangles in position by face detection again, since a certain deviation is of course accepted. You can only delete all faces in the preview (context menu) and search again.

Maik
Comment 3 Maik Qualmann 2022-10-15 13:18:33 UTC 
Erasing face rectangles while at the same time rescanning the image for faces is a difficult writing situation. A separate task was started in digiKam-7.x.x, which leads to problems. For digiKam-8.0.0 this process is now executed directly. I therefore close the bug as fixed for digiKam-8.0.0. If you were able to create a GDB log, reopen it.

Maik
Comment 4 Jens 2022-10-15 17:25:16 UTC 
OK. Yes, I realize this may lead to race conditions.
Then can we please have a "Delete this face and rescan image" option?
If I decide certain face rectangles are incorrect and want to rescan the corresponding images, I cannot delete the face because then the image is gone from the view.
Comment 5 Maik Qualmann 2022-10-15 18:09:30 UTC 
The option to delete everything and scan again is available in the maintenance tool. We can also add this action to the People sidebar as a scan option.

Maik
Comment 6 Maik Qualmann 2022-10-15 18:33:54 UTC 
Git commit 79d1ebd082b0bb3e84011d55504c306b347e098c by Maik Qualmann.
Committed on 15/10/2022 at 18:33.
Pushed by mqualmann into branch 'master'.

add rescan Option to the face settings widget

M  +11   -26   core/utilities/facemanagement/widgets/facescanwidget.cpp

https://invent.kde.org/graphics/digikam/commit/79d1ebd082b0bb3e84011d55504c306b347e098c