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 using a clustering algorithm, 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, wherein the analysis of the cluster map and the digital image includes: identifying edges in the digital image; and refining the pixel groupings in the cluster map by comparing the identified edges with borders of the pixel groupings and removing pixels that are outside of the identified edges from the pixel groupings; and storing an indication of the identified objects in a processor-accessible memory system.