CCTV knife detection: a kitchen knife on a night street

This clip uses the same camera and the same street as the handgun clip. The camera is fixed high on the corner of a shop and looks down a lit pavement at night, with parked cars and a street beyond. Because the view is identical, the only thing that changes between the two clips is the object in the person's hand.

The person wears a dark jacket, a cap and grey trousers. A large kitchen knife is held low in the right hand, down by the hip. It is clearly visible from about the midpoint of the clip, when the person turns and walks past the shop door. Before that the knife is mostly hidden by the body and the angle, which is the situation a knife detector has to handle: a thin object, held low, against a busy background.

No detector overlay is drawn on this clip. You see the scene as a camera would record it, without boxes or scores. That makes it useful for judging how visible the knife is to a person watching the footage, and how small it is compared with the rest of the frame.

The knife was generated into the empty scene, and the original footage without it is shown lower on this page. The dataset for this scenario contains person and knife labels in YOLO and COCO formats, and a free sample can be downloaded to check the labels against your own detector.