1. A processor-implemented method of determining whether a feature of interest is present, comprising: receiving an image; mapping the image to a template using at least one predetermined nonlinear divergence transform to yield a mapped image, wherein the at least one predetermined nonlinear divergence transform comprises a transfer function with at least one nodal point positioned so as to cause the feature of interest to exhibit a characteristic color space signature; and determining whether the characteristic color space signature is present in the mapped image; wherein the at least one predetermined nonlinear divergence transform is determined by applying at least one initial divergence transform to an image containing a known feature that is substantially similar to the feature of interest, and adjusting the at least one initial divergence transform so that the known feature diverges from other features in the image by exhibiting the characteristic color space signature.