1. An article recognition apparatus comprising: an interface configured to acquire a photographic image of a table on which a plurality of articles to be recognized is disposed; a database that stores a reference value for each article to be recognized in the plurality of articles; and a processor configured to detect identification patterns in the photographic image, to recognize each article in the plurality of articles corresponding to one of the detected identification patterns, to detect image regions occupied by the plurality of articles in the photographic image, to determine article region information from the detected image regions, and to determine that an unrecognized article is in the plurality articles disposed on the table if the reference values for each article recognized by detection of identification patterns does not match the article region information.