A cooperative document understanding method among multiple recognition procedures

The main objective of document understanding is to extract and classify the meaningful data automatically from documents. Some researches, concerning this issue, have already been reported. However, these methods are not always successful because the recognition procedures analyze document images on the basis of only physical coordinate values of compositive items. This paper proposes a more advanced method based on the spatial relationships among neighboring segments of compositive items, in addition to the geometric aspects. The knowledge about documents is not a single layer, but organized as multi-level layers: knowledge about layout structures, knowledge about item sequences and knowledge about item properties. Three kinds of knowledge are not only specified hierarchically, but also interrelated mutually between the layout recognition, item recognition and character recognition procedures