US Patent 7765474 Electronic-document management system and method

An electronic-document management system includes an acquisition unit, an edit unit, first and second storage units, a generation unit and an output unit. The acquisition unit acquires a target electronic document. The edit unit edits the acquired target electronic document. The first storage unit stores the target electronic document edited by the edit unit and a feature value of the edited target electronic document in association with each other. The generation unit generates meta-information of the edited target electronic document, which comprises a feature value of the edited target electronic document. The second storage unit stores the meta-information of the edited target electronic document and a feature value of the meta-information of the edited target electronic document in association with each other. The output unit outputs the feature value of the meta-information of the edited target electronic document as reference information of the edited target electronic document.