1. A system for performing classification through generative models of features occurring in an image, comprising: stored category-conditional probability distributions of features occurring in a plurality of training images that are each assigned to a category; and a classifier, comprising: a feature identifier to identify the features occurring in an unclassified image; a likelihood evaluator to determine category-conditional likelihoods for the identified features using the category-conditional probability distributions for each category; and a categorizer to assign the unclassified image to one such category based upon the category-conditional likelihoods.