1. A method of selecting representative images from a group, comprising: selecting a dissimilarity measure by which to compute dissimilarities between features of respective images in the group; computing dissimilarities between the images in the group, based on the selected dissimilarity measure; determining a relative dissimilarity between each image and the other images in the group, based on the relative dissimilarity between the feature of the image and the features of the other images in the group; and selecting an image in the group as a representative image for display, using the relative dissimilarity of the image as a probability bias in the selection, wherein a distribution of dissimilarities of respective features of images in the group from the average value is chosen according to the selected dissimilarity measure, and wherein the determining step determines the relative dissimilarity of a candidate image by calculating the ratio of the likelihood probability of the feature of the candidate image being a medoid feature to the sum of the likelihood probabilities of all of the features in the other images in the set being the medoid feature.