8. The form recognition apparatus according to claim 7 , further comprising: a storage unit capable of storing a database in which headline wordings that may appear in a unit table structure being a unit for entering one or more pieces of related data in the form are defined in a hierarchical structure for each unit table structure, wherein the table structure determination unit determines the entire table structure existing in the form image, referring to a database stored in the storage unit.
8. The form recognition apparatus according to claim 7 , further comprising: a storage unit capable of storing a database in which headline wordings that may appear in a unit table structure being a unit for entering one or more pieces of related data in the form are defined in a hierarchical structure for each unit table structure, wherein the table structure determination unit determines the entire table structure existing in the form image, referring to a database stored in the storage unit. 10. The form recognition apparatus according to claim 8 , wherein the hierarchical structure includes a first layer in which one or more headline wordings are defined, a second layer in which a first representative headline being a headline wording that represents a headline wording defined in the first layer and can be replaced with another headline wording and a third layer in which a second representative headline being a headline wording ordered higher than the first representative headline in the table structure, the position specification unit extracts a range of the unit table structure having the second representative headline, on the basis of an extraction result of the second representative headline, by the character string extraction unit and specifies the position in the range, focusing on the first representative headline replaceable with another headline wording recognized in the extracted range and a character string recognized as data in the unit table structure, and the phrase creation unit creates the headline wording by specifying a first representative to be added to a position specified in the range by the position specification unit.