1. A method for detecting objects and background in a digital image, and the method implemented at least in part by a data processing system and comprising the steps of: receiving the digital image representing a scene; identifying range information associated with the digital image, the range information including distances of pixels in the scene from a known reference location; generating a cluster map based at least upon an analysis of the range information and the digital image, the cluster map grouping pixels of the digital image by their distances from a viewpoint; identifying objects in the digital image based at least upon an analysis of the cluster map and the digital image; and storing an indication of the identified objects in a processor-accessible memory system.