1. An annotation system comprising: memory which stores: a structured prediction model which represents predicted correlations between values assumed by labels in a set of labels; instructions for: generating feature-based predictions for values of labels in the set of labels based on features extracted from an image; predicting a value for at least one label from the set of labels for the image based on the feature-based label predictions, and the structured prediction model, and, when the instructions include instructions for receiving an assigned value for at least one label from the set of labels for the image, the predicted value being also based on an assigned value for at least one other label, if one has been assigned; and a processor for executing the instructions.