1. An image processing method, comprising the steps of: receiving a spectral image of an object; extracting an input pixel from the spectral image; converting the input pixel into a vector, each element in the vector of the input pixel representing a reflectance of a respective one of a plurality of spectral bands; providing spectral signatures of a plurality of endmembers; correlating a plurality of test spectral images with the spectral signatures of the endmembers; creating a map of the spectral signatures of the endmembers based on the correlations with the plurality of test vectors; identifying the spectral signatures of endmembers having a correlation with the input pixel that exceeds a predetermined threshold, including the substep of applying the input pixel to the map to determine which spectral signatures of the endmembers have a correlation with the input pixel that exceeds the predetermined threshold; and determining a combination of the endmembers present in the input pixel based on the identified endmembers.