Abstract: In various examples there is an apparatus with a memory storing a video captured by a capture device, the video depicting a scene comprising two or more people in an environment. The apparatus has a self-supervised neural network which takes at least one frame of the video as input and in response, computes a prediction of at least four points in the frame which depict four points on a plane of the scene. A processor computes, from the four points, a plan view of the scene and detects two or more people in the plan view of the scene. The processor computes, for individual pairs of people depicted in the plan view, an estimate of shortest distance between the people in the pair.