1. A method for generating concept structures from signature reduced clusters (SRCs), comprising: retrieving at least one current SRC including a cluster of signatures respective of a plurality of multimedia data elements (MMDEs); generating at least one metadata for each signature of the cluster of signatures; identifying a number of repetitions of a metadata of the at least one generated metadata; determining whether the number of repetitions of the metadata of the at least one generated metadata, within the at least one current retrieved SRC, exceeds a predefined repetition threshold; upon determining that the number of repetitions of the metadata exceeds the predefined repetition threshold, identifying the at least one metadata as representative of the SRC; comparing the representative metadata of the current retrieved SRC to metadata that is representative of at least one previously generated SRC to determine a metadata match; and upon determining that the metadata match, identifying the current retrieved SRC and the matching previously generated SRC as a concept structure, wherein the concept structure is represented by the representative matching metadata from both the current retrieved SRC and the at least one previously generated SRC.