• Title/Summary/Keyword: License plate detection

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Design of a Recognizing System for Vehicle's License Plates with English Characters

  • Xing, Xiong;Choi, Byung-Jae;Chae, Seog;Lee, Mun-Hee
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.3
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    • pp.166-171
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    • 2009
  • In recent years, video detection systems have been implemented in various infrastructures such as airport, public transportation, power generation system, water dam and so on. Recognizing moving objects in video sequence is an important problem in computer vision, with applications in several fields, such as video surveillance and target tracking. Segmentation and tracking of multiple vehicles in crowded situations is made difficult by inter-object occlusion. In the system described in this paper, the mean shift algorithm is firstly used to filter and segment a color vehicle image in order to get candidate regions. These candidate regions are then analyzed and classified in order to decide whether a candidate region contains a license plate or not. And then some characters in the license plate is recognized by using the fuzzy ARTMAP neural network, which is a relatively new architecture of the neural network family and has the capability to learn incrementally unlike the conventional BP network. We finally design a license plate recognition system using the mean shift algorithm and fuzzy ARTMAP neural network and show its performance via some computer simulations.

Vehicle Information Recognition and Electronic Toll Collection System with Detection of Vehicle feature Information in the Rear-Side of Vehicle (차량후면부 차량특징정보 검출을 통한 차량정보인식 및 자동과금시스템)

  • 이응주
    • Journal of Korea Multimedia Society
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    • v.7 no.1
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    • pp.35-43
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    • 2004
  • In this paper, we proposed a vehicle recognition and electronic toll collection system with detection and classification of vehicle identification mark and emblem as well as recognition of vehicle license plate to unman toll fee collection system or incoming/outcoming vehicles to an institution. In the proposed algorithm, we first process pre-processing step such as noise reduction and thinning from the rear side input image of vehicle and detect vehicle mark, emblem and license plate region using intensity variation informations, template masking and labeling operation. And then, we classify the detected vehicle features regions into vehicle mark and emblem as well as recognize characters and numbers of vehicle license plate using hybrid and seven segment pattern vector. To show the efficiency of the proposed algorithm, we tested it on real vehicle images of implemented vehicle recognition system in highway toll gate and found that the proposed method shows good feature detection/classification performance regardless of irregular environment conditions as well as noise, size, and location of vehicles. And also, the proposed algorithm may be utilized for catching criminal vehicles, unmanned toll collection system, and unmanned checking incoming/outcoming vehicles to an institution.

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A license plate detection method based on contour extraction that adapts to environmental changes (주변 환경 변화에 적응하는 윤곽선 추출 기반의 자동차 번호판 검출 기법)

  • Pyo, Sung-Kook;Lee, Gang-seong;Park, Young-Soo;Lee, Sang-Hun
    • Journal of the Korea Convergence Society
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    • v.9 no.9
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    • pp.31-39
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    • 2018
  • In this paper, we proposed a license plate detection method based on contour extraction that adapts to environmental changes. The proposed method extracts contour lines using DoG (Difference of Gaussian) to remove unnecessary noise parts in the contour extraction process. Binarization was applied in ugly outline images, and erosion and dilation operations were used to emphasize the contour of the character part. Then, only the outline of the ratio of the characters of the plate was extracted through the ratio of the width and height of the characters. And the case where the outline is the longest is estimated by estimating the characters of the license plate. For the experiment, we applied 130 image data to license plate on the front of the vehicle, oblique environment, and environment images with various backgrounds. I also experimented with motorcycle images of different license plate patterns. Experimental results showed that the detection rate of the oblique image was 93% and that of the various background environment was 70% in the motorcycle image but 98% in the front image.

A Study on Recognition of Both of New & Old Types of Vehicle Plate (신, 구 차량 번호판 통합 인식에 관한 연구)

  • Han, Kun-Young;Woo, Young-Woon;Han, Soo-Whan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.10
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    • pp.1987-1996
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    • 2009
  • Recently, the color of vehicle license plate has been changed from green to white. Thus the vehicle plate recognition system used for parking management systems, speed and signal violation detection systems should be robust to the both colors. This paper presents a vehicle license plate recognition system, which works on both of green and white plate at the same time. In the proposed system, the image of license plate is taken from a captured vehicle image by using morphological information. In the next, each character region in the license plate image is extracted based on the vertical and horizontal projection of plate image and the relative position of individual characters. Finally, for the recognition process of extracted characters, PCA(Principal Component Analysis) and LDA(Linear Discriminant Analysis) are sequentially utilized. In the experiment, vehicle license plates of both green background and white background captured under irregular illumination conditions have been tested, and the relatively high extraction and recognition rates are observed.

Color Segmentation of Vehicle License Plates in the RGB Color Space Using Color Component Binarization (RGB 색상 공간에서 색상 성분 이진화를 이용한차량 번호판 색상 분할)

  • Jung, Min Chul
    • Journal of the Semiconductor & Display Technology
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    • v.13 no.4
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    • pp.49-54
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    • 2014
  • This paper proposes a new color segmentation method of vehicle license plates in the RGB color space. Firstly, the proposed method shifts the histogram of an input image rightwards and then stretches the image of the histogram slide. Secondly, the method separates each of the three RGB color components and performs the adaptive threshold processing with the three components, respectively. Finally, it combines the three components under the condition of making up a segment color and removes noises with the morphological processing. The proposed method is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiments were conducted by using real vehicle images. The results show that the proposed algorithm is successful for most vehicle images. However, the method fails in some vehicles when the body and the license plate have the same color.

An Ensemble Classifier Based Method to Select Optimal Image Features for License Plate Recognition (차량 번호판 인식을 위한 앙상블 학습기 기반의 최적 특징 선택 방법)

  • Jo, Jae-Ho;Kang, Dong-Joong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.1
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    • pp.142-149
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    • 2016
  • This paper proposes a method to detect LP(License Plate) of vehicles in indoor and outdoor parking lots. In restricted environment, there are many conventional methods for detecting LP. But, it is difficult to detect LP in natural and complex scenes with background clutters because several patterns similar with text or LP always exist in complicated backgrounds. To verify the performance of LP text detection in natural images, we apply MB-LGP feature by combining with ensemble machine learning algorithm in purpose of selecting optimal features of small number in huge pool. The feature selection is performed by adaptive boosting algorithm that shows great performance in minimum false positive detection ratio and in computing time when combined with cascade approach. MSER is used to provide initial text regions of vehicle LP. Throughout the experiment using real images, the proposed method functions robustly extracting LP in natural scene as well as the controlled environment.

License Plates Detection Using a Gaussian Windows (가우시안 창을 이용한 번호판 영역 검출)

  • Kang, Yong-Seok;Bae, Cheol-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37A no.9
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    • pp.780-785
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    • 2012
  • In the current study, the authors propose a method for extracting license plate regions by means of a neural network trained to output the plates center of gravity. The method is shown to be effective. Since the learning pattern presentation positions are defined by random numbers, a different pattern is submitted to the neural network for learning each time, which enables it to form a neural network with high universality of coverage. The article discusses issues of the optimal learning surface for a license plate covered by the learning pattern, the effect of suppression learning of the number and headlight sections, as well as the effect of learning pattern enlargement/reduction and of concentration value conversion. Results of evaluation tests based on pictures of 595 vehicles taken at an underground parking garage demonstrated detection rates of 98.5%.

Recognition of a New Car Plate using Color Information and Error Back-propagation Neural Network Algorithms (컬러 정보와 오류역전파 신경망 알고리즘을 이용한 신차량 번호판 인식)

  • Lee, Jong-Hee;Kim, Jin-Whan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.5
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    • pp.471-476
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    • 2010
  • In this paper, we propose an effective method that recognizes the vehicle license plate using RGB color information and back-propagation neural network algorithm. First, the image of the vehicle license plate is adjusted by the Mean of Blue values in the vehicle plate and two candidate areas of Red and Green region are classified by calculating the differences of pixel values and the final Green area is searched by back-propagation algorithm. Second, our method detects the area of the vehicle plate using the frequence of the horizontal and the vertical histogram. Finally, each of codes are detected by an edge detection algorithm and are recognized by error back-propagation algorithm. In order to evaluate the performance of our proposed extraction and recognition method, we have run experiments on a new car plates. Experimental results showed that the proposed license plate extraction is better than that of existing HSI information model and the overall recognition was effective.

The automatic recognition of the plate of vehicle using the correlation coefficient and hough transform (상관계수와 하프변환을 이용한 차량번호판 자동인식)

  • Kim, Kyoung-Min;Lee, Byung-Jin;Lyou, Kyoung;Park, Gwi-Tae
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.5
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    • pp.511-519
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    • 1997
  • This paper presents the automatic recognition algorithm of the license number in on vehicle image. The proposed algorithm uses the correlation coefficient and Hough transform to detect license plate. The m/n ratio reduction is performed to save time and memory. By the correlation coefficient between the standard pattern and the target pattern, licence plate area is roughly extracted. On the extracted local area, preprocessing and binarization is performed. The Hough transform is applied to find the extract outline of the plate. If the detection fails, a smaller or a larger standard pattern is used to compute the correlation coefficient. Through this process, the license plate of different size can be extracted. Two algorithms to each separate number are proposed. One segments each number with projection-histogram, and the other segments each number with the label. After each character is separated, it is recognized by the neural network. This research overlomes the problems in conventional methods, such as the time requirement or failure in extraction of outlines which are due to the processing of the entire image, and by processing in real time, the practical application is possible.

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2D Artificial Data Set Construction System for Object Detection and Detection Rate Analysis According to Data Characteristics and Arrangement Structure: Focusing on vehicle License Plate Detection (객체 검출을 위한 2차원 인조데이터 셋 구축 시스템과 데이터 특징 및 배치 구조에 따른 검출률 분석 : 자동차 번호판 검출을 중점으로)

  • Kim, Sang Joon;Choi, Jin Won;Kim, Do Young;Park, Gooman
    • Journal of Broadcast Engineering
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    • v.27 no.2
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    • pp.185-197
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    • 2022
  • Recently, deep learning networks with high performance for object recognition are emerging. In the case of object recognition using deep learning, it is important to build a training data set to improve performance. To build a data set, we need to collect and label the images. This process requires a lot of time and manpower. For this reason, open data sets are used. However, there are objects that do not have large open data sets. One of them is data required for license plate detection and recognition. Therefore, in this paper, we propose an artificial license plate generator system that can create large data sets by minimizing images. In addition, the detection rate according to the artificial license plate arrangement structure was analyzed. As a result of the analysis, the best layout structure was FVC_III and B, and the most suitable network was D2Det. Although the artificial data set performance was 2-3% lower than that of the actual data set, the time to build the artificial data was about 11 times faster than the time to build the actual data set, proving that it is a time-efficient data set building system.