1. A method for processing data, comprising: receiving a depth map, captured by an imaging assembly, of a scene containing one or more objects positioned in relation to a planar surface corresponding to a floor on which at least one of the objects is positioned, the depth map comprising a matrix of pixels, at least some of which have respective pixel depth values and correspond to respective locations in the scene; using a digital processor, processing the depth map so as to identify and generate a parametric model of the planar surface by: computing local normals at the pixels in the depth map; processing respective depth values of at least some of the pixels in order to predict a height of the imaging assembly with respect to each pixel; clustering the pixels according to the local normals and to the height of the imaging assembly predicted with respect to the pixels; and choosing as the floor a cluster of the pixels that is located, according to the predicted height of the imaging assembly for the cluster, at the lowest plane in space among a set of clusters containing more than a predetermined minimal area in the depth map; and segmenting one or more of the objects in the scene by removing the planar surface represented by the parametric model from the depth map.