Advantages of Multileves Document Analysis

• page
• table, text block
• table cell
• paragraph, picture
• line
• word, picture within a line
• letter (character)

• Any object in this hierarchy is composed of lower-level objects, e.g.
  • letters make words,
  • words make lines, etc.
• The OCR technlogoy analyses the document from the top down:

  • it first divides the page into larger objects,
  • which in turn it divides into smaller objects etc. until it reaches the level of characters.
• Once the characters have been singled out and recognized, a reverse process begins: The program assembles individual objects into larger objects that will be combined into the complete page at the end. This procedure is called Multilevel Document Analysis, or MDA.

• If an OCR program makes a recognition error at one of the higher levels of analysis (e.g. if it mistakes a paragraph for a picture), there is very little chance that it will come up with the right result — the document will be recognized incorrectly.

• To achive highest recognition accuracy, the ABBYY OCR technology analyses documents slightly differently than other OCR engines:
  • When recognizing objects of any level, the ABBYY technology is guided by the IPA principles.
  • The process starts by forming hypotheses about the nature of the objects and purposefully verifies its hypotheses.
  • At the same time it takes into account the distinctive features it has detected on the document and saves the newly acquired information for future use (self-learning).

More information:

• OCR & PDF Features
• Document & Layout Analysis for OCR