19. A non-transitory computer-readable medium having instructions stored thereon that, in response to execution, cause a system including a processor to perform operations comprising: matching probe metadata included in an uploaded media item with reference metadata representing a structured text description of a candidate media item in a reference database based upon a matching function value, wherein the probe metadata includes a free-form text description of the uploaded media item; determining a confidence score for the candidate media item based upon a scoring function comprised of a first product of the matching function value and a first sum of one and a candidate weight, the first product divided by a second sum of a normalized unstructured function value for the probe media item and a second product of the candidate weight and a normalized structured function value of the candidate media.
20. The non-transitory computer-readable medium of claim 19 , the operations further comprising selectively filtering the candidate media item based upon the confidence score.