Bug 508733

Summary: Duplicates found on Similarity Search but not displayed for review (no thumbnails)
Product: [Applications] digikam Reporter: MikeE <michaelenglish2>
Component: Searches-SimilarityAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: metzpinguin
Priority: NOR    
Version First Reported In: 8.6.0   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: Version Fixed/Implemented In: 8.8.0
Sentry Crash Report:
Attachments: Screenshot of selected album
Scanning wrong folder
Screenshot of settings
Screenshot of duplicates being found but not listed

Description MikeE 2025-08-25 20:26:21 UTC
SUMMARY
Duplicates found on search (621 on this occasion) but then don't display as thumbnails.

STEPS TO REPRODUCE (all 'For selected Album')
1. Rebuild fingerprints (from Maintenance - Tools).
2. Find Duplicates (from Maintenance - Tools) - 621 duplicates found.

OBSERVED RESULT
1. Looked in Duplicates tab but no results shown in the list (or sometimes just one random photo), regardless of filters/scope.

EXPECTED RESULT
1. Should see 621 duplicates appear as thumbnails.

SOFTWARE/OS VERSIONS

digiKam: 8.6.0
KDE Frameworks: 6.10.0
Qt: Using 6.8.1 and built against 6.8.1
Windows 11 Version 24H2
Build ABI: x86_64-little_endian-llp64
Kernel: winnt 10.0.26100

ADDITIONAL INFORMATION
I have tried switching tabs. I've tried scanning for Faces and then going back to duplicates. I've tried right-clicking on the Album under Albums and Find Duplicates, all give the same result, no result. I have also done a Database clean, including cleaning Thumbnails, then Find Duplicates, it finds them (as before) but does not display them. I have tried re-starting DigiKam. I've tried Tool - Maintenance - Scan for New Items, no difference.
Comment 1 MikeE 2025-08-25 20:40:52 UTC
I changed the similarity range from 70-100 to 65-100 and now they are all displayed (after another system restart).

So that is a workaround, but I believe this is still a bug.
Comment 2 MikeE 2025-08-25 20:43:05 UTC
(In reply to MikeE from comment #1)
> I changed the similarity range from 70-100 to 65-100 and now they are all
> displayed (after another system restart).
> 
> So that is a workaround, but I believe this is still a bug.

Actually, I spoke too soon. It has listed abou 10 duplicates with their thumbnails, even though it found 621 in the folder.
Comment 3 Maik Qualmann 2025-08-25 20:47:52 UTC
I can't reproduce the problem in digiKam-8.8.0. You have to go to the Similarity Search tab in the left sidebar and select a duplicate group in the list view to display thumbnails. I wouldn't use the maintenance tool, but rather the left sidebar.

Maik
Comment 4 MikeE 2025-08-25 20:55:05 UTC
Created attachment 184440 [details]
Screenshot of selected album
Comment 5 MikeE 2025-08-25 20:56:25 UTC
Comment on attachment 184440 [details]
Screenshot of selected album

So I've attached a screenshot of my selected album.
I'll try upgrading to the version you mentioned, to see if that helps.
Comment 6 MikeE 2025-08-25 21:04:51 UTC
I've upgraded to 8.7.0 but no improvement.
Note that there may be some underlying problem. When using the left-hand pane for Similarity or People, it is stuck on using an album I was using a few hours ago ('2007'). I have select '2016' as per screenshot, but I can tell that it's actually scanning 2007 - see second screen shot.

(digiKam: 8.7.0
KDE Frameworks: 6.12.0
Qt: Using 6.8.3 and built against 6.8.3
Windows 11 Version 24H2
Build ABI: x86_64-little_endian-llp64
Kernel: winnt 10.0.26100)
Comment 7 MikeE 2025-08-25 21:08:20 UTC
Created attachment 184441 [details]
Scanning wrong folder

Even though 2016 folder is selected, when clicking 'Update Fingerprints', the product continues to scan a folder I was using earlier this evening (2007). No amount of re-starting the product and the Windows 11 laptop, upgrading of the product, refreshing the tabs, or cleaning of the database seems to do anything to help.
Comment 8 MikeE 2025-08-25 21:22:54 UTC
Things seem to be getting worse. I've tried another folder '2008' and it done 'Update Fingerprints' (I have to do this from Maintenance-Tools, otherwise it keeps defaulting to 2007). It said it had updated 1,408 fingerprints. Then I click 'Find Duplicates' (also within Maintenance-Tools) and it says Items scanned:0, Duplicates 1,408.
Comment 9 Maik Qualmann 2025-08-26 05:53:52 UTC
Fingerprints are always created for all albums; fingerprints have nothing to do with album selection.

I suspect an incorrect setting for the duplicate search.
Please show your other duplicate settings.

Maik
Comment 10 Maik Qualmann 2025-08-26 05:55:30 UTC
Here is the link to the digiKam manual for the duplicate search:

https://docs.digikam.org/en/left_sidebar/similarity_view.html#find-duplicates

Maik
Comment 11 MikeE 2025-08-26 08:19:33 UTC
Created attachment 184449 [details]
Screenshot of settings

Screenshot of all settings attached. I thought it would be good to see the result when I click 'Find Duplicates', to include that screenshot, so I ran it, and this time it worked. But I didn't change anything.
Comment 12 Maik Qualmann 2025-08-26 09:30:40 UTC
I suspect you didn't create the corresponding fingerprints. The maintenance tool only creates fingerprints for the selected albums, which I think is a bad idea, as it's easy to forget which albums have been fingerprinted.

The button in the Duplicates tab updates/creates missing fingerprints for all albums; I recommend this approach.

In digiKam-8.8.0, we've sped up the display of duplicate items in the list view (separate thread). Even with 10,000 entries, it could take minutes for entries to be displayed and digiKam to be usable again.

Maik
Comment 13 MikeE 2025-08-30 13:36:54 UTC
Hi Maik
I've used the Update Fingerprints in the Similarity tab and get the same result after clicking 'Find Duplicates' - lots of duplicates found but none displayed. When I change the accuracy level, I get a few (like 5 out of the 600). I'm having to Remove Duplicates, and then looks through all the Trash to try and work out if I want to delete it or not. This doesn't really work for me.
Maybe once I've got all my photos sorted like this, it'll be easier and work better as an incremental thing when I have some new photos.
Thanks. I do still think this is a bug but if others are not getting the problem, then I suppose we may as well close this item?
Thanks
Mike
Comment 14 Maik Qualmann 2025-08-30 18:52:26 UTC
I don't understand what you're saying. You say duplicates are found, but none are displayed. That's a contradiction. You have to select a row in the duplicate list to display the corresponding duplicates.

If you don't see any entries in the duplicates list view, this may be an OpenGL issue. As a test, enable the forced software OpenGL option in the digiKam settings under Miscellaneous -> System, then restart digiKam.

Maik
Comment 15 MikeE 2025-08-31 16:08:56 UTC
Created attachment 184609 [details]
Screenshot of duplicates being found but not listed

Hi Maik
I agree it's a contradiction but that's what it does - its says it finds them (and I think it does find them, because if I say 'Remove Duplicates', it puts them in the Trash, but it refuses to dispaly them, which makes the function almost useless to me (and is the main reason I went for Digikam :-() The Open GL was already ticked, but I unticked it, restarted DigiKam, and then re-ticked it, restarted DigiKam, but it made no difference: same behaviour.
Mike
Comment 16 Maik Qualmann 2025-10-07 19:31:28 UTC
Git commit 8db8b8747639fe8233b3bbce8d142bc27befc4ea by Maik Qualmann.
Committed on 07/10/2025 at 19:30.
Pushed by mqualmann into branch 'master'.

try to fix the non-display of duplicate items

M  +1    -4    core/utilities/fuzzysearch/findduplicatesview.cpp

https://invent.kde.org/graphics/digikam/-/commit/8db8b8747639fe8233b3bbce8d142bc27befc4ea
Comment 17 Maik Qualmann 2025-10-08 06:25:34 UTC
Git commit e99919ccdedb9bb89ebbe5e54559e0f2b9678df3 by Maik Qualmann.
Committed on 08/10/2025 at 06:24.
Pushed by mqualmann into branch 'master'.

this should resolve the issue of duplicate items not being displayed
We create the item list ourselves and don't need the signal from the album manager.
FIXED-IN: 8.8.0

M  +1    -1    NEWS
M  +12   -15   core/utilities/fuzzysearch/findduplicatesview.cpp

https://invent.kde.org/graphics/digikam/-/commit/e99919ccdedb9bb89ebbe5e54559e0f2b9678df3
Comment 18 Maik Qualmann 2025-10-12 12:36:38 UTC
Git commit 4a5e254674ee6bd1802849728242496d16eddd7f by Maik Qualmann.
Committed on 12/10/2025 at 12:35.
Pushed by mqualmann into branch 'master'.

fix counter of duplicate images

M  +18   -16   core/libs/database/haar/haariface.cpp

https://invent.kde.org/graphics/digikam/-/commit/4a5e254674ee6bd1802849728242496d16eddd7f
Comment 19 MikeE 2025-10-26 14:35:24 UTC
Disaster - I accidentally deleted all the database elements (faces, similarity). I can't go through 20,000 photos again, each with an average of 4 faces on it. But thanks for the help on this! Happy to close.