14. A cross descriptor learning system comprising: storage storing a plurality of unlabeled exemplars; a descriptor extraction unit extracting descriptors from said unlabeled exemplars; an automatic descriptor labeler generating labels for each extracted descriptor from other extracted said descriptors; a cross descriptor predictor predicting labels for said each extracted descriptor from said each extracted descriptor and labels generated for each extracted descriptor; and a label combination unit combining labels for said each extracted descriptor from said cross descriptor predictor with labels from said automatic descriptor labeler, each one of the combined said labels being applied to a corresponding unlabeled exemplar.
21. A cross descriptor learning system as in claim 14 , wherein said automatic descriptor labeler comprises: storage storing a plurality of labeled exemplars; an extractor extracting descriptors from said labeled exemplars; and a label predictor developer developing a label predictor from extracted said descriptors from said plurality of labeled exemplars, said descriptors extracted from said unlabeled descriptors being automatically labeled by one said label predictor.