1. A method comprising: selecting, by one or more computing devices, an image associated with a street address that includes a building number; identifying, by the one or more computing devices, a portion of the image containing characters associated with building numbers; extracting, by the one or more computing devices, an alphanumeric value from the characters within the portion of the image; comparing, by the one or more computing devices, the alphanumeric value to the building number of the street address; displaying, by the one or more computing devices, to a human operator and dependent upon the result of such comparison, the alphanumeric value and the portion of the image containing characters; receiving, by the one or more computing devices, from a human operator, an indication of whether the alphanumeric value is a building number; and storing, by the one or more computing devices, an association between the alphanumeric value and the image dependent upon the indication.