1. A method for estimating a visible vector representation for pixels in an infrared image, the method comprising: receiving an infrared (IR) image captured using a N-band infrared imaging system, said IR image comprising a plurality of pixels with each pixel having an IR band vector of N intensity values collected for that pixel; and for each pixel of interest in said infrared image: using a search metric to search a spectra database of vector samples to identify a visible-IR set with intensity values closest to this pixel's IR band vector; and estimating a visible vector representation for said pixel based upon the visible portion corresponding to said closest visible-IR vector.