라즈베리 파이를 이용한 무선 자동차번호판 영역 추출 모듈 개발

• Published in: 멀티미디어학회논문지 Vol. 18; no. 10; pp. 1172 - 1179
• Main Authors: 김동경(Dong-Kyung Kim), 우종호(Chong-Ho Woo)
• Format: Journal Article
• Language: Korean
• Published: 한국멀티미디어학회 2015
• Subjects: 전자/정보통신공학; LPR System; Wifi Direct; Raspberry Pi; OpenCV; License Plate Extraction
• ISSN: 1229-7771; 2384-0102
• DOI: 10.9717/kmms.2015.18.10.1172

A wireless license plate region extracting module is proposed for LPR system controlling multiple gates. This module is cheaply implemented using Raspberry Pi which is open source and high performance. First, as the upper 1/3 of the captured image is discarded as it has no useful information on license plate. Using the OpenCV libraries the edge image is got by Canny algorithm after applying Gaussian filtering to gray image, and the labeling is conducted for 4 consecutive numbers in license plate. These numbers are located using various decision equations, and expanding the numbers region the final license plate region can be extracted. The result image is transferred to Server using wifi direct. Using the proposed module it becomes easy to set up and maintain the LPR system. The experimental results showed that the successful extracting rate was 98.4% using 500 car images with 640 × 480 resolution.