The Detection of Slanted Car License Plate Region

기울어진 차량 번호판 영역의 검출

  • 문성원 (충북대학교 정보산업공학과) ;
  • 장언동 (충북대학교 정보통신공학과) ;
  • 송영준 (충북대학교 정보통신공학과)
  • Published : 2004.09.01


This paper proposes a method of the car license plate recognition from digital camera image. Lots of technology advancement has been accomplished for the least several years. The key issue for recognition rate improvement has been the extraction of correct area on the plate. In the previous studies, the information from an edge or an color on a plate hasn't been used but some declination also taken into account in most cases due to the difficulty of area extraction on a tilted plate The proposed method focuses on transforming a slant plate image to the normalized form to be recognized. It shows good robustness on situations defined by a variety of locations, slants and heights of the license plate, because it detects the edge of license plate by using both the color information and linear regression method. The computer simulation shows that the proposed method records 92% detection rates of license plate and can recognize characters of slant plate with about 50 degrees.


Line Fitting;Biliner Transformation;Image Retrieval