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Adaptive Local Binarization Method for Recognition of Vehicle License Plates

  • Byeong Rae Lee
  • Kyungsoo Park
  • Hyunchul Kang
  • Haksoo Kim
  • Chungkyue Kim
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3322)

Abstract

A vehicle license-plate recognition system is commonly composed of three essential parts: detecting license-plate region in the acquired images, extracting individual characters, and recognizing the extracted characters. But in the process, the problems like damage of license-plate and unequal light effect make it difficult to detect accurate vehicle license-plate region and to extract letters in that region. In this paper, to extract characters accurately in the license- plate region, a local adaptive binarization method which is robust under non-uniform lighting environment is proposed. To get better binary images, region- based threshold correction based on a prior knowledge of character arrangement in the license-plate is applied. With the proposed binarization method, 96% of 650 sample vehicle license-plates images are correctly recognized. Compared to existing local threshold selection methods, about 5% of improvement in recognition rate is obtained with the same recognition module based on LVQ.

Keywords

Character Region License Plate Recognition Module Binarization Method Recognition Failure 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2004

Authors and Affiliations

  • Byeong Rae Lee
    • 1
  • Kyungsoo Park
    • 2
  • Hyunchul Kang
    • 2
  • Haksoo Kim
    • 3
  • Chungkyue Kim
    • 4
  1. 1.Dept. of Computer ScienceKorea National Open UniversitySeoulKorea
  2. 2.Dept. of Information and Telecommunication EngineeringUniversity of IncheonIncheonKorea
  3. 3.Dept. of Information and Telecommunication EngineeringSungkonghoe UniversitySeoulKorea
  4. 4.Dept. of Computer Science and EngineeringUniversity of IncheonIncheonKorea

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