1. A method of determining alignment of images in high dimensional feature space, said method comprising: registering a source image of a reference modality to a target image of a second modality with an algorithm based upon a measure of information affinity present in both of the source and target image to create a registered image; extracting a plurality of feature vectors from the registered image for each of the source and target images; plotting a distribution of the feature vectors on an entropic graph; determining edge lengths between the feature vectors from the entropic graph; and determining a similarity measure of one of an α-divergence estimate or an α-affinity estimate based upon these edge lengths to indicate whether the source and target image are sufficiently registered.