Document understanding has attained a level of maturity that requires migration from ad-hoc experimental systems, each of which employs its own set of assumptions and terms, into a solid, standard frame of reference, with generic deenitions that are agreed upon by the document understanding community. The logical structure of a document conveys semantic information that is beyond the document's character string contents. To capture this additional semantics, document understanding must relate the document's physical layout to its logical structure. This work provides a formal deenition of the logical structure of text-intensive documents. A generic framework using a hierarchy of textons is described for the interpretation of any text-intensive document logical structure. The recursive deenition of textons provides a powerful and exible tool that is not restricted by the size or complexity of the document. Frames are analogously used as recursive constructs for the physical structure description. To facilitate the reverse engineering process which is required to derive the logical structure, we describe DAFS| a Document Attribute Format Specii-cation and demonstrate how our framework can serve as a conceptual framework for enhancements of DAFS.

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Document understanding has attained a level of maturity that requires migration from ad-hoc experimental systems, each of which employs its own set of assumptions and terms, into a solid, standard frame of reference, with generic deenitions that are agreed upon by the document understanding community. The logical structure of a document conveys semantic information that is beyond the document's character string contents. To capture this additional semantics, document understanding must relate the document's physical layout to its logical structure. This work provides a formal deenition of the logical structure of text-intensive documents. A generic framework using a hierarchy of textons is described for the interpretation of any text-intensive document logical structure. The recursive deenition of textons provides a powerful and exible tool that is not restricted by the size or complexity of the document. Frames are analogously used as recursive constructs for the physical structure description. To facilitate the reverse engineering process which is required to derive the logical structure, we describe DAFS| a Document Attribute Format Specii-cation and demonstrate how our framework can serve as a conceptual framework for enhancements of DAFS.