Bug 432764

Summary: Face detection (!) with few results
Product: [Applications] digikam Reporter: Christian <chrispopp>
Component: Faces-DetectionAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED WORKSFORME    
Severity: normal CC: caulier.gilles, metzpinguin
Priority: NOR    
Version: 7.2.0   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: Version Fixed In: 7.2.0
Sentry Crash Report:

Description Christian 2021-02-10 21:21:26 UTC 
Hi, 

I'm using face detection and recognition. With 7.2.0-rc the recognition improved a lot, thanks for this handy functionality! I was told the algorithm works better, if I don't mark the faces manually. So I'd like to work with face detection, but I would have expected much more faces being detected by the functionality.

Scenario: I tested with a album/folder of about 25 group fotos (typical school and club fotos, 20-50 people per foto) and 10 other fotos with 1-5 people. Face detection results in only 10 detected faces, not a single one from the group fotos. Also tried to lower accuracy parameter with the hope that it also aplies to detection, but with no improvement.

Is there a minimum size for faces on fotos to be detected? (If I had to estimate such a parameter, I'd say faces needed to cover more than 1/10 of length/width of a foto to be detected.) How can I improve the results of face detection?

Thanks,
Christian

SOFTWARE/OS VERSIONS
Windows: Windows 10
Comment 1 Maik Qualmann 2021-02-10 21:33:07 UTC 
Activate the Yolo v3 detection model in the person settings. It's slower, but will detect all of the faces in the images.

Maik
Comment 2 Christian 2021-02-10 22:15:46 UTC 
Got it, detection approx. 95%, thanks!!
Comment 3 Maik Qualmann 2021-02-11 06:40:11 UTC 
Which sensitive level have you set? 95% are still not enough for me without knowing the image. Use a sensitive level around 60-70%.

Maik
Comment 4 Christian 2021-02-11 07:31:18 UTC 
Sensitivity level 70%. I'd say for half of the group photos detection is 100%, most of the others there is always one or two faces of 20-30 missed out.

Then there are two special photos: a group of 20 at carnival, without masks, with detection about 50%; another group of about 80, so rather tiny faces, none of them detected. 

Please let me know, if I can help you with variation of settings or photos to send over.
Comment 5 Maik Qualmann 2021-02-12 07:03:39 UTC 
I tested various group images from the internet or images from my collection of weddings. Face recognition with Yolo v3 is between 95-100%. People who either turn their heads to the side or are partially covered by others are not recognized. That's its ok. I close the bug.

Maik