The present invention provide a method for extracting a tree structure by using image analysis results of an actual document and generating a flexible layout model. A tree structure and layout model are newly generated by automatically extracting the tree structure in accordance with document image analysis...http://www.google.com.hk/patents/US5555362?utm_source=gb-gplus-share專利 US5555362 - Method and apparatus for a layout of a document image
