1. A system for content recognition, search, and retrieval in visual data, the system comprising one or more processors configured to perform operations of: receiving unlabeled visual data as an input; extracting a set of activity-agnostic content descriptors from the unlabeled, visual data with a hierarchical content descriptor module having a plurality of levels, resulting in a set of generated activity-agnostic content descriptors, wherein each level of the hierarchical content descriptor module generates a distinct set of activity-agnostic content descriptors; indexing the generated activity-agnostic content descriptors with a hierarchical content indexing module having a plural of levels corresponding to the plurality of levels of the hierarchical content descriptor module, resulting in a set of indexed content descriptors; wherein each level of the content indexing module comprises a distinct set of indexed content descriptors from a corresponding level in the hierarchical content descriptor module; storing the unlabeled visual data, the set of generated activity-agnostic content descriptors, and the set of indexed content descriptors in a storage module; searching the storage module and retrieving visual data containing, a content of interest based on a user query; refining the user query based on feature weighting; and presenting the visual data containing the content of interest to the user.