Vertical-Edge-Based Car-License-Plate Detection Method
Vertical-Edge-Based Car-License-Plate Detection Method
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DOI：
10.1109/tvt.2012.2222454
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发表时间：
2013-01-01
影响因子：
6.8
通讯作者：
Ismail, Alyani
中科院分区：
文献类型：
--
作者：
Al-Ghaili, Abbas M.;Mashohor, Syamsiah;Ismail, Alyani
本文提出了一种快速车牌检测方法，并给出了三个主要贡献。首先，我们提出了一种基于灰度值对比的快速垂直边缘检测算法（VEDA），提高了CLPD方法的速度。采用自适应阈值法（AT）对输入图像进行二值化处理后，提出了一种不希望线消除算法（ULEA）对图像进行增强，然后应用VEDA算法。第二个贡献是我们提出的CLPD方法处理由网络摄像机拍摄的非常低分辨率的图像。在VEDA检测到垂直边缘后，根据颜色信息突出显示所需的板材细节。然后，根据统计和逻辑运算提取候选区域。最后，检测到LP。第三个贡献是，我们将VEDA与Sobel算子在准确性、算法复杂性和处理时间方面进行了比较。结果表明，该算法的边缘检测性能准确，处理速度比Sobel算法快5 ~ 9倍。在复杂度方面，我们使用了一个大o符号模块，得到如下结果：VEDA的复杂度降低了K-2倍，而K-2表示的是Sobel的掩码大小。结果表明，CLPD方法的计算时间为47.7 ms，满足实时性要求。
This paper proposes a fast method for car-license-plate detection (CLPD) and presents three main contributions. The first contribution is that we propose a fast vertical edge detection algorithm (VEDA) based on the contrast between the grayscale values, which enhances the speed of the CLPD method. After binarizing the input image using adaptive thresholding (AT), an unwanted-line elimination algorithm (ULEA) is proposed to enhance the image, and then, the VEDA is applied. The second contribution is that our proposed CLPD method processes very-low-resolution images taken by a web camera. After the vertical edges have been detected by the VEDA, the desired plate details based on color information are highlighted. Then, the candidate region based on statistical and logical operations will be extracted. Finally, an LP is detected. The third contribution is that we compare the VEDA to the Sobel operator in terms of accuracy, algorithm complexity, and processing time. The results show accurate edge detection performance and faster processing than Sobel by five to nine times. In terms of complexity, a big-O-notation module is used and the following result is obtained: The VEDA has less complexity by K-2 times, whereas K-2 represents the mask size of Sobel. Results show that the computation time of the CLPD method is 47.7 ms, which meets the real-time requirements.