1. A method of detecting an object in an image at a client device, comprising the steps of: receiving, from a server, a two dimensional image of a scene, the scene being captured by a camera and the image comprising an object located within the scene; receiving, from the server, position data, the position data being indicative of the position of the object within the image; receiving, from the server, an outline representation of the object at that position, the outline representation defining, for each pixel position of a plurality of pixel positions within a bounding box segment of the image corresponding to the received position, whether a respective pixel position of the plurality of pixel positions represents the object or a background, the bounding box segment of the image being determined by the server as a portion of an entirety of the image including the object; and on the basis of said outline representation, detecting the object in the image.