Help, I accidentally a wigglegram: a script that mines photo libraries for stereo images

A post on the personal blog lmao.center describes an accidental experiment: its author, an indecisive photographer who takes many frames from slightly different angles and never clears a camera roll, realised that years of photographs could be reassembled into wigglegrams. The write-up reached the front page of Hacker News, where it collected 580 points.

What a wigglegram is

A wigglegram is a kind of stereo image made by looping several frames together, like a GIF, so that the viewpoint shifts slightly and the picture appears to gain depth. The post quotes a Reddit commenter, "suavecorn", who explains the format, and another, "aka_hochstapler", who notes the effect is quite convincing. The author's camera roll, it turned out, was already full of the raw material: pairs and runs of shots taken from almost the same spot.

Finding frames with perceptual hashing

The idea for automating the search came from reverse image search. Perceptual hashing, the technique TinEye and similar services use, produces a fingerprint that — unlike a cryptographic function such as SHA-1 — shares more bits with hashes of similar-looking images than with dissimilar ones. The author wrote a script to hash an entire photo library, then compared hashes pairwise by Hamming distance; a distance of about ten proved to be a good boundary for "same scene, slightly different angle". Hashing itself is quick, the author notes, but downloading photos from iCloud is not.

Hundreds of wigglegrams, most of them accidents

Extracting the matching pairs produced hundreds of wigglegrams. A few were taken deliberately, but most were true accidents, and that changes their character: many come out less "stereoscopic" and more "kinescopic" — small unintentional movies. The examples span travel and landscapes (Space Mountain, Block Island, DeLand, Notting Hill, Perugia), animals (cats, a dog, a pigeon), design work in progress and sculpture, including a shot of an Olivetti typewriter.

Point it at your own library

The script is published on GitHub. On a Mac it can run directly against an iCloud Photos library, or it can be pointed at any directory of pictures instead. The post is tagged personal and photography, and the author describes the results as fun — the kind of payoff a hoarded camera roll was apparently waiting for.