17. The method as recited in claim 15 , wherein said simultaneous sparse approximation process is executed upon at least one selectively grouped set of image data vectors.
15. A method for processing electronically captured images formed by a plurality of spectral components comprising the steps of: electronically capturing image data with complex spectral content, the image data including a plurality of image data vectors defined with respect to a spatial image plane; establishing a plurality of candidate spectral components; actuating a discovery processor to execute a simultaneous sparse approximation process upon image data vectors of at least a portion of the captured image, actuating the discovery processor to adaptively discover for the image data vectors a set of core spectral signatures defined in terms of candidate spectral components automatically selected from a general dictionary; and, selectively matching at least one individual captured image data vector to at least a portion of said core spectral signature set to decompose said image data vector to a representation as a linear combination of the portion of said core spectral signature set; whereby constituent features of the captured image portion corresponding to said selectively matched core spectral signatures are discriminated according to said linear combination thereof.