Retrieval of document images using layout knowledge

Document image archives are increasingly used to replace paper and microfilm filing. Usually those archives are combined with a database management system or with full text retrieval to search the documents. An additional retrieval method to search already known images in personal document image archives using layout knowledge is presented. This knowledge can be the size, position, and color of layout objects, but also the position of keywords. A layout editor is proposed, which allows the interactive generation of a layout query using object oriented drawing functions. The layout search can be done in a relational database, which was filled with the help of layout recognition methods. For better results and performance special search methods and structures are necessary. Examples for those methods are quad trees to locate layout objects at absolute positions, neighborhood tables to find object pairs with certain spatial relationships, and full text search in page or object areas