1. An information processing apparatus comprising: a network creating unit that creates a network in which respective characters of a plurality of character recognition results are represented as nodes, and in which nodes of adjacent character images are connected with a link; a first determining unit that determines a first candidate boundary in the network; a second determining unit that determines a second candidate boundary different from the first candidate boundary in the network; and an extracting unit that extracts, as to-be-searched objects, a plurality of candidate character strings from a set of candidate character strings each formed of nodes between the first candidate boundary and the second candidate boundary.