1. A system comprising: a point cloud receiver configured to receive a point cloud comprising a plurality of points, each point representing a spatial point in an image; a processor configured to: arrange the points into a hierarchical search tree, with a lowest level comprising a plurality of leaf nodes, where each leaf node corresponds to a point of the point cloud, the search tree comprising a plurality of hierarchical levels with tree nodes in each of the hierarchical levels, the nodes being vertically connected to each other though the hierarchy by branches, wherein at least one moment of a property of the descendant nodes is stored in each tree node; determine geometric information of the points located within a region, by identifying the highest level tree nodes where all of the descendent leaf nodes are contained within the region and selecting the leaf nodes for the points where no sub-tree is entirely contained within the region, such that the points falling within the region are represented by the smallest number of nodes and performing statistical operations on the nodes representing the points in the region, the statistical operations being determined from the moments of the properties stored within the identified tree nodes, wherein zeroth order, first order, and second order moments of the position of the points are stored in the nodes, and the geometric information includes descriptors of features in the point cloud; calculate a covariance matrix from the moments stored within the nodes for the points in a region defined around a selected point and determining a descriptor from said covariance matrix; and compare the feature descriptors with a database of feature descriptors for a plurality of objects.