Using graph matching techniques to wrap data from PDF documents

ABSTRACT

Wrapping is the process of navigating a data source, semi-automatically extracting data and transforming it into a form suitable for data processing applications. There are currently a number of established products on the market for wrapping data from web pages. One such approach is Lixto [1], a product of research performed at our institute.Our work is concerned with extending the wrapping functionality of Lixto to PDF documents. As the PDF format is relatively unstructured, this is a challenging task. We have developed a method to segment the page into blocks, which are represented as nodes in a relational graph. This paper describes our current research in the use of relational matching techniques on this graph to locate wrapping instances.

REFERENCES

• 1: Robert Baumgartner , Sergio Flesca , Georg Gottlob, Visual Web Information Extraction with Lixto, Proceedings of the 27th International Conference on Very Large Data Bases, p.119-128, September 11-14, 2001
• 2: William J. Christmas , Josef Kittler , Maria Petrou, Structural Matching in Computer Vision Using Probabilistic Relaxation, IEEE Transactions on Pattern Analysis and Machine Intelligence, v.17 n.8, p.749-764, August 1995 [doi>10.1109/34.400565 ]
• 3: Josep Lladoós , Enric Martí , Juan Josée Villanueva, Symbol Recognition by Error-Tolerant Subgraph Matching between Region Adjacency Graphs, IEEE Transactions on Pattern Analysis and Machine Intelligence, v.23 n.10, p.1137-1143, October 2001 [doi>10.1109/34.954603 ]

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.7 DOCUMENT AND TEXT PROCESSING
      I.7.5 Document Capture
          Subjects: Document analysis

Additional Classification:
  H. Information Systems
  H.3 INFORMATION STORAGE AND RETRIEVAL
      H.3.3 Information Search and Retrieval

General Terms:
Algorithms, Experimentation

Keywords:
PDF, document understanding, graph matching, logical structure, wrapping