20. The method of claim 19 , further comprising: combining the hyponym probability values of each of the accessed plurality of digital images before generating the subset hierarchical tree.
20. The method of claim 19 , further comprising: combining the hyponym probability values of each of the accessed plurality of digital images before generating the subset hierarchical tree. 21. The method of claim 20 , wherein combining the hyponym probability values of each of the accessed plurality of digital images includes calculating a normalized log sum of the hyponym probability values for each hyponym term occurring in the accessed plurality of digital images.