Guideline for specifying layout knowledge

Abstract

Until today, many layout recognition/analysis methods have been proposed, but the guideline for knowledge representation applicable to documents which should be analyzed newly is not always discussed directly. This paper addresses such a subject. Generally, the documents can be categorized into the appropriate document types on a basis of the features of layout structures. Then, the processing mechanisms are assessed with a view to establishing the criteria for selecting the knowledge representation means appropriate to the document types. First, we define the physical layout structure and logical layout structure in addition to the traditional concepts of layout structure and logical structure. Second, we define the document type on the basis of the relationship between the physical layout structure and logical layout structure. Third, we make the knowledge representation means and the processing mechanisms clear under the document types. Finally, we show a criterion or guideline for knowledge representation means and processing mechanisms with respect to the logical layout structure and physical layout structure. For this discussion, our basic view is derived from our document understanding methods which we have developed for several different documents.