1. A method of producing classification maps from multispectral data comprising the following steps: a. transforming multispectral data into a binary format wherein said data is arranged in a predetermined spacial pattern; b. encoding the transformed data onto an optical film medium by varying the optical characteristics of the film medium to provide binary coding and preserving said spacial pattern in the transformed data when encoded onto said optical medium; and c. holographically correlating the encoded transformed data with correlating data representing a selected spectral signature to produce a single-class classification map, said holographic correlating step comprising the cross correlating of data for a single resolution element of a multispectral element with all of the resolution elements of said scanner and wherein said single-class classification maps are photographed on high gamma photographic film using controlled development so that only light intensities above a predetermined threshold value representing a selected minimum holographic cross-correlating will expose the film and so that above said threshold the light intensities will expose the film in proportion to the value of the intensity, said film being subsequently developed and projected so that the brightness of each spot will be an indication of the degree to which the corresponding resolution element belongs to the particular class.