1. A method of processing image data, the method comprising: receiving image data comprising a set of feature vectors of a first dimensionality, the feature vectors corresponding to a class of objects; generating a set of projected vectors of a second dimensionality, lower than the first dimensionality, by applying a variable projection to each feature vector in the set of feature vectors; processing the set of projected vectors to generate a model for the class of objects; and applying a projection to the model to generate an object classification model, of the first dimensionality, for the class of objects.