12. The method according to claim 9 , wherein the extracting the one or more keywords includes extracting the one or more keywords by performing a natural language analysis for a portion which is estimated to have a meaning as a sentence.
9. An image processing method, comprising: scanning image information regarding an original document, the original document including character addition information added manually to at least one character string in the original document; extracting layout information regarding character regions and the character addition information added to the at least one character string within the character regions from the image information; converting the character regions included in the layout information into character information; extracting one or more keywords comprising the at least one character string from the character information in response to determining that the character addition information added to the at least one character string has a predefined image characteristic; searching by use of the one or more keywords and generating meta-information based on information retrieved by the searching; and generating an electronic document according to a description of a predetermined format by adding the meta-information to the character information.