An Algorithm for the Automatic Analysis of Characters Located on Car License Plates

  • Dariusz Frejlichowski
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7950)


The method for the analysis of signs visible on car license plates is described and experimentally evaluated in this paper. The algorithm is applied to the recognition of characters localised on car license plates, used in Poland. Emphasis is put on the especially complex cases — i.e. objects distorted by noise and occlusion — which are the most difficult and challenging tasks of the discussed problem and can be caused, for example, by bad weather conditions. The influence of poor quality images is another source of the problem. The modified UNL transform is applied to solve the problem. This is an algorithm for contour shape representation and recognition, which is not only invariant to affine transformations, but also robust against noise and occlusion. The algorithm is based on the transformation of points belonging to an object that has been extracted from the image from Cartesian to polar coordinates.


License Plate Outer Contour License Plate Recognition Vehicle License IEEE Signal Processing Society 
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 2013

Authors and Affiliations

  • Dariusz Frejlichowski
    • 1
  1. 1.Faculty of Computer Science and Information TechnologyWest Pomeranian University of Technology, SzczecinSzczecinPoland

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