1. A method comprising: obtaining a set of low-level features from an image; generating a high-dimensional generative representation of the image based on the low-level features; generating a lower-dimensional representation of the image based on the high-dimensional generative representation of the image; generating classifier scores based on classifiers and on one or more of the high-dimensional generative representation and the lower-dimensional representation, wherein each classifier uses the one or more of the high-dimensional generative representation and the lower-dimensional representation as an input, and wherein each classifier is associated with a respective category; and generating a combined representation for the image based on the classifier scores and the lower-dimensional representation.