1. A non-transitory computer readable storage medium comprising a computer readable program for generating compact iris representations based on a database of iris images, wherein the computer readable program when executed on an iris recognition computer system causes the iris recognition computer system to perform the steps of: computing genuine and imposter score distributions for full-length iris codes for iris images in a database, where the full-length iris codes include a plurality of portions corresponding to circumferential rings in an associated iris image; identifying and retaining code portions that have a contribution that provides separation between imposter and genuine score distributions relative to a threshold by measuring a discriminatory capacity of rows of the full-length iris codes and retaining the code portions having the discriminatory capacity equal to or greater than the threshold; measuring a correlation between remaining code portions; and transforming the full-length iris codes into compact iris codes by making mated and unmated pairs of iris codes, sampling one or more middle bands of the iris; and generating a subset of the remaining code portions having low correlations within the subset by extracting regions of the iris code with high discriminatory capacity, wherein a file size of the full-length iris codes is reduced during the transformation so that transformed compact iris codes use less storage space than full-length iris codes.