Fast Structural Matching for Document Image Retrieval through Spatial Databases

The structure of document images plays a significant role in document analysis thus considerable efforts have been made towards extracting and understanding document structure, usually in the form of layout analysis approaches. In this paper, we first employ Distance Transform based MSER (DTMSER) to efficiently extract stable document structural elements in terms of a dendrogram of key-regions. Then a fast structural matching method is proposed to query the structure of document (dendrogram) based on a spatial database which facilitates the formulation of advanced spatial queries. The experiments demonstrate a significant improvement in a document retrieval scenario when compared to the use of typical Bag of Words (BoW) and pyramidal BoW descriptors.