Method and system for estimating the geometry of a scene

Abstract

A method of obtaining real world scale information for a scene includes obtaining at least one image of a plurality of objects in a scene; detecting at least some of the objects in the at least one image as corresponding to pre-determined objects; generating a 3D reconstruction of the scene based on the image content of the at least one image; determining a relative size of each object in the 3D reconstruction of the scene in at least one dimension, the relative size being defined in dimensions of the generated 3D reconstruction; where the relative size of each object is determined based on a distance between at least two points corresponding to that object as transformed into 3D space; obtaining a size probability distribution function for each object detected in the at least one image, each size probability distribution function defining a range of sizes in at least one dimension that a corresponding object is likely to possess in real world units; resealing the size probability distribution function for each detected object based on a corresponding relative size of that object in the 3D reconstruction; and estimating a geometry of the scene in real world units by combining the re-scaled probability distribution function for at least one detected object with the re-scaled probability distribution function for at least one other detected object.