1. An image dictionary creating apparatus comprising: an information obtaining section that obtains a result of a character recognition processing on an input image; a character classifying section that classifies a character image included in the input image into a plurality of character image groups based on the result of the character recognition processing obtained by the information obtaining section; a typical pattern determining section that determines a typical image pattern constituting the input image based on the character image classified into the character image groups by the character classifying section; and an identification information assigning section that assigns identification information for identifying the image pattern, to the typical image pattern determined by the typical pattern determining section.