1. A method for searching a database of digital media assets, comprising: a processor receiving a search query; the processor analyzing the search query to extract a specialized search condition corresponding to a specialized semantic concept; the processor selecting, from a pre-existing ontology of indexers, a specialized indexer based on a determination that the selected specialized indexer can be used to identify digital media assets that correspond to the specialized semantic concept; the processor analyzing the search query to extract a general search condition corresponding to a related higher level semantic concept; the processor identifying, from a database of digital media assets, a subset of digital media assets that satisfy the general search condition responsive to general metadata for each of the digital media assets; the processor applying the selected specialized indexer to the subset of digital media assets to determine specialized metadata for a digital media asset in the subset of digital media assets, wherein the specialized metadata provides an indication of whether the digital media asset corresponds to the specialized semantic concept; and the processor converting the specialized indexer into a general indexer based at least on a frequency with which the specialized semantic concept is queried, wherein the processor is configured to convert the specialized indexer into the general indexer based further on a computational cost associated with the specialized indexer, wherein the general indexer is applied to the digital media assets independent of a search query, wherein the general indexer is operable to identify a digital media asset that corresponds to a higher level semantic concept and determine the general metadata for the identified digital media asset based at least upon an analysis of pixel data associated with the digital media asset, and wherein the general metadata provides an indication of the higher level semantic concept to which the identified digital media asset corresponds.