The pattern was tuned against an open-source detector until the software stopped reporting a human; a person just sees a loud Hawaiian print.
In a demonstration for 404 Media, a camera feeding a video monitor drew a green box around someone standing in front of it and tagged the box with the word PERSON. When the person raised a shirt called Digital Camouflage in front of their body, box and tag vanished; both came back once the shirt was moved aside, every time the test was repeated.
Simon Weckert made the shirt to protest the cameras that switched on in August at Berlin’s Kottbusser Tor, a busy U-Bahn stop in the Kreuzberg district — the first police-run object-recognition cameras in the city, according to 404 Media. They can pick out a person stretched out on the pavement, Weckert told the outlet, which leaves homeless people at risk of being flagged and having officers sent to them.
By Weckert’s account, object-detection software never grasps what makes someone a person. It picks up statistical regularities drawn from millions of training images: edges and texture at the shallow end of a network, and deeper in, the shape of a head and shoulders and the proportions of limbs.
Digital Camouflage turns that training against itself with a jumbled swirl of pink, orange and green forms. The saturated colors strongly activate a detection network’s first processing layers, while the overlapping shapes distort the body’s outline so the detector cannot reassemble the pieces into a single human figure.
Not knowing which system Berlin’s cameras used, Weckert installed YOLO on a camera of his own — a family of open-source algorithms for spotting objects in real time, some version of which runs in a great many image-recognition cameras. He fed it random patterns, then rotated parts, changed colors and flipped sections, reading off each time how sure the algorithm was that it was looking at a person.
He stops short of claiming the shirt beats what is deployed at Kottbusser Tor. It works against YOLO, he told 404 Media, and that is as far as he will go: on his own website he says the shirt guarantees nobody anonymity, since people outside a government system have no way to put it to an independent test.
The shirt sells for roughly $88. The aim goes beyond letting individuals slip past surveillance, he said: he wants people to understand the systems and to see that pushing back is possible. “It’s not like we just have to accept what the lawmakers and police are doing,” he said.
The print is meant to go out of date. Just as fashion brands release seasonal updates, he said, he plans a new camouflage design each time a new version of YOLO comes out.