Automatically adjust thumbnails of recognized faces?

[Markoise]

I recently had to change my Nextcloud provider. Unfortunately, you then have to start from 0 again. I have now painstakingly processed around 32000 images. Since the face recognition is not great, I had to cluster many recognized faces manually.

By the way: It's a pity that there is no export function (e.g. via the User Migration app or as a download link in the settings).

During this lengthy process, thumbnails are initially created for recognized faces. With my old provider, these were automatically updated with newer faces. But that doesn't happen now. For example, a 30-year-old thumbnail is used for my face. Despite the newly added photos, the old thumbnail is still used.

I have not manually added a thumbnail to any face. As far as I know, this will never change again.

Am I wrong that the thumbnails are automatically adjusted over time, or how does that work?

[marcelklehr]

Hi @Markoise
This is the code that selects the prview image on demand:

recognize/lib/Db/FaceDetectionMapper.php

Lines 268 to 294 in d479da6

	public function findDetectionForPreviewImageByClusterId(int $clusterId) : FaceDetection {
	$qb = $this->db->getQueryBuilder();
	$qb->select(array_map(fn ($col) => 'd.'.$col, FaceDetection::$columns))
	->from('recognize_face_detections', 'd')
	->where($qb->expr()->eq('d.cluster_id', $qb->createPositionalParameter($clusterId)))
	->andWhere($qb->expr()->gt($qb->createFunction('d.x - d.width * 0.5'), $qb->createFunction('0')))
	->andWhere($qb->expr()->gt($qb->createFunction('d.y - d.height * 0.5'), $qb->createFunction('0')))
	->andWhere($qb->expr()->gt($qb->createFunction('1 - (d.x + d.width) - d.width * 0.5'), $qb->createFunction('0')))
	->andWhere($qb->expr()->gt($qb->createFunction('1 - (d.y + d.height) - d.height * 0.5'), $qb->createFunction('0')))
	->groupBy('d.id')
	->addOrderBy('d.height', 'DESC')
	->addOrderBy('d.width', 'DESC')
	->setMaxResults(1);
	try {
	return $this->findEntity($qb);
	} catch (DoesNotExistException $e) {
	$qb = $this->db->getQueryBuilder();
	$qb->select(array_map(fn ($col) => 'd.'.$col, FaceDetection::$columns))
	->from('recognize_face_detections', 'd')
	->where($qb->expr()->eq('d.cluster_id', $qb->createPositionalParameter($clusterId)))
	->groupBy('d.id')
	->addOrderBy('d.height', 'DESC')
	->addOrderBy('d.width', 'DESC')
	->setMaxResults(1);
	return $this->findEntity($qb);
	}
	}

It currently doesn't take into account newer images explicitly. So, on some databases it may prefer newer pictures and on some it will always take the oldest ones.

[Markoise]

Hi @marcelklehr
That would be something for a future improvement, wouldn't it?

[marcelklehr]

Yep, definitely :)