1. A computer-executed method comprising: accessing an image comprising an unidentified key phrase in image format; processing a portion of the image associated with the unidentified key phrase using a character recognition algorithm to generate a list of candidate key phrases in text format; accessing, by a computer processor, a plurality of social media content items in text format authored by users of a social networking system, the social media content items each comprising at least one key phrase previously associated with the image and at least one of the candidate key phrases; determining, by the computer processor, for each candidate key phrase, a count of the number of the content items comprising that candidate key phrase and at least one of the key phrases previously associated with the image; selecting, by the computer processor, one of the candidate key phrases as being the unidentified key phrase based on the determined count of the content items in each set; and sending content associated with the image to one or more users of the social networking system based on the social media content items including the selected candidate key phrase.
4. The computer-executed method of claim 1 , wherein the candidate key phrases in text format are filtered based on an identified language of the text in the social media content items.