Relations

Collections that grow over years pick up near-copies: the same picture saved twice at different sizes, a recoloured version, a sketch and the finished piece, an edit of someone else’s work. Relations let you say how two images are related, and monbooru helps you find the pairs.

There are four kinds:

Marking a pair Not related is a decision too: monbooru won’t suggest it again.

To declare a relation yourself, use Add a relation on an image’s page. When monloader downloads a booru post that names a parent post, the two are linked as a derivative once both are in your gallery.

Collections are a separate, lighter way to group images.

Finding candidate pairs#

monbooru computes a perceptual hash for every image, a fingerprint of what it looks like that survives resizing and re-encoding, and suggests pairs of images whose fingerprints are close. New images are checked as they arrive. Relations -> Find new pairs checks everything added since the last time, and the nightly run can do it for you (see Maintenance).

Settings -> Relations -> pHash matching distance says how different two images may look and still be paired: lower means fewer pairs, but surer ones.

A fingerprint can’t see that a recolour or a redraw belongs with its original, since the pixels are too different. Their tags can. So monbooru also pairs images that share rare tags, the ones few of your images carry. This only works once your images are tagged, and it costs a full pass over the library each time, so switch it off under Settings -> Relations if your library is big and mostly untagged. The match strength there sets how much tagging two images must share; lowering it finds more variants and makes a longer queue.

The swipe session#

Relations -> Start a session shows you the queued pairs side by side, one at a time. Decide what each pair is, or skip it for later. The line between the two images says why they were paired: how close their fingerprints are, which rare tags they share, or both.

Marking a pair Duplicate keeps the image on the left as the original and offers to delete the file on the right. If the right one has tags the left one lacks, you can copy them over first.

Browsing and undoing#

Relations -> Browse relations lists everything you declared, one tab per kind, Not related included. From there you can unlink a pair, break up a group, or send a pair back to a session with Review again when you change your mind.

Cleaning up duplicates#

Relations -> Duplicates has two tools, for two different problems:

• Duplicate images goes through the duplicate groups you declared, two different files you said are the same picture. It deletes the copies and keeps the original, and Copy tags first moves the copies’ tags onto the original.
• Duplicate files goes through files that are byte-for-byte identical but stored in more than one place on disk. monbooru already treats them as one image, so this just deletes the extra files.