Vector-based segmentation of text connected to graphics in engineering drawings

  • Dov Dori
  • Liu Wenyin
Document Image Analysis and Recognition
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1121)


A method for segmentation of text that may be connected to graphics in engineering drawings is presented. It consists of three steps: growing individual characterbox regions, using a recursive merging scheme by stroke linking; merging the detected characterboxes into a textbox and determining its orientation; and re-segmenting the textbox back into the refined characterbox that can be input to an OCR subsystem. The method can segment dimensioning text as well as other classes of text. It handles both isolated and touching characters, aligned at any slant. The capability of segmenting characters that touch either themselves or graphics, which is an important feature in handling real life drawings, is obtained by focusing on intermediate vector information rather that on the raw pixel data. We present the details of the algorithm and show both successful and unsuccessful examples from an experimental set of 36 dimensioning textboxes, in which 94% segmentation rate was achieved with 3% false alarm rate.


Text Segmentation Engineering Drawing Interpretation Primitive Recognition 


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Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • Dov Dori
    • 1
  • Liu Wenyin
    • 1
  1. 1.Faculty of Industrial Engineering and ManagementTechnion-Israel Institute of TechnologyHaifaIsrael

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