1. A method for analysis of image data for subject content, said method comprising the steps of: (a) performing at least one pass through a frame of said image data; and (b) generating a base Terrain Map from said pass through said frame of said image data, said base Terrain Map comprising a plurality of base data members that indicate the content of said image data; (c) generating at least one upper tier Terrain Map Summary hierarchically removed from said Terrain Map, said upper tier Terrain Map Summary comprising a plurality of members based upon or indicating the content of said base data members.