共查询到19条相似文献,搜索用时 546 毫秒
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一种基于边缘颜色的彩色车牌定位算法 总被引:1,自引:0,他引:1
为解决车牌识别中车牌定位问题,根据车牌局域颜色变化、车牌宽高、车牌中字符数及车牌中字符颜色变化等特征,提出了基于边缘颜色的车牌定位算法;通过实验,证明了该算法能够有效地克服光线和天气变化的影响,具有很强的抗干扰性能、定位精度高达98.4%. 相似文献
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对眼睛快速、准确的定位是对运动中的人脸进行实时识别的重要前提.提出了1种结合人脸特征、相关模板匹配和改进的积分投影的方法,实现了快速有效的眼睛定位.在图像预处理的基础上,结合最大类间方差阈值分割法的二值化处理、数学形态学的开运算、相关模板匹配以及改进的积分投影得出人脸区域,然后根据人脸特征间的几何关系,利用改进的积分投影及其统计数据的峰值位置确定眼球的中心位置.实验表明,该方法具有很好的定位效果,对不同角度、不同方向的倾斜人脸、脸部表情及姿势变化等具有很好的鲁棒性. 相似文献
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复杂背景下的多车牌定位技术研究 总被引:1,自引:0,他引:1
针对竖直边缘检测的车牌定位方法在多车牌定位中的梯度分割阈值的问题,提出一种改进的阈值选取方法。即先将图像进行区域划分,然后采用区间梯度均值和Otsu阈值的平均值作为新的阈值来分割区域图像。该方法对车牌污染、车牌远近不一致等情况具有良好的适应性。同时,针对从车牌候选区域中去除伪车牌的问题,提出了利用新的主连通域分析的方法和颜色、宽高比等特征来从候选区域中正确提取多个车牌的方法。该方法能够较好地去除复杂背景下的类似于车牌背景的颜色伪车牌,以及和车牌字符有着相似纹理特征的伪车牌。测试结果表明,该方法车牌定位率超过97.3%,去除伪车牌后的车牌定准率超过88.5%,同时在时间上能够较好地满足实时路况中准确定位出车牌的需求。 相似文献
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D. -J. Kang 《International Journal of Automotive Technology》2009,10(2):205-210
In the last decade, vehicle identification systems have become a central element in many applications involving traffic law
enforcement and security enhancement, such as locating stolen cars, automatic toll management, and access control to secure
areas. As a method of vehicle identification, license plate recognition (LPR) systems play an important role and a number
of such techniques have been proposed. In this paper, we describe a method for segmenting the main numeric characters on a
license plate by introducing dynamic programming (DP) that optimizes the functionality describing the distribution of the
intervals between characters, the alignment of the characters, and the threshold difference used to extract the character
blobs. The proposed method functions very rapidly by applying the bottom-up approach of the DP algorithm and also robustly
by minimizing the use of environment-dependent image features such as color and edges. 相似文献
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盲图像质量评价在智能交通系统中的应用 总被引:1,自引:0,他引:1
针对交通系统图像的特点,构建了盲图像质量评价在智能交通系统中应用的框架。对于获取到的交通图像首先进行预处理(包括车身区域分割和车牌检测),然后对影响交通图像质量的亮度、对比度及清晰度分别进行评价。对实际获取的图像利用算法进行了验证,实验结果表明,算法可以较好地对交通图像进行分类且评价结果与主观评价一致。 相似文献
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为解决机动车牌图像倾斜将对其字符分割与识别带来不利的影响,提出一种基于主元分析(PCA)的车牌图像倾斜校正新方法。在该方法中,PCA被用于求取坐标变换矩阵以进行图像旋转修正。将原始的像素坐标矩阵经过中心化后转换为2维协方差矩阵,再奇值分解为能反映图像倾斜方向的2维对角矩阵和坐标变换矩阵。算法的时间复杂度分析与试验结果均表明:相对于Hough等搜索倾角的校正方法,PCA方法缩短了计算时间1 ̄2个数量级,并且在污迹、光照不均等条件下也能获得较好效果。 相似文献
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License plate extraction method for identification of vehicle violations at a railway level crossing
B. K. Cho S. H. Ryu D. R. Shin J. I. Jung 《International Journal of Automotive Technology》2011,12(2):281-289
The primary cause of most railroad accidents is vehicle entry into railway level crossings despite warning messages. To identify
drivers who violate railway level crossing regulations, vehicle license plate recognition can be applied at railway level
crossings. The purpose of this paper is to present an effective method for extracting the license plate region from vehicle
images taken at railway level crossings. The method proposed in this paper uses the variation in the gray-level values across
the image of a license plate. For license plate region extraction, the character region is first recognized by identifying
the character width and the difference between the background region and the character region. The license plate region is
then extracted by finding the inter-character distance in the plate region. In addition, the license plate type is identified
by the difference in the gray-level value between the background region and the character region. The proposed method is effective
in solving the current challenges in extracting the license plate region from the damaged frames of license plates issued
for domestic use, including new types of license plates. According to the experimental results, the proposed method yields
a high extraction rate of 99.5% for vehicle license plates. 相似文献
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车牌定位是车牌自动识别系统的关键。提出了一种以纹理特征为主要手段,以彩色特征为辅助手段的多特征定位算法,对不同背景和光照条件下的各类车牌图像进行了实验,结果表明该算法是一种可行的方法。 相似文献
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车辆牌照的自动识别是智能交通系统中的一项重要技术,而车辆牌照的定位又是车牌识别的关键点之一。文章依据二值化图像中车牌区域跳变频率高的事实,提出一种算法来确定车辆牌照在原始图像中的水平位置和垂直位置,从而定位车辆牌照。实验结果表明本算法处理速度较快、便于实现。 相似文献
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M. -K. Kim 《International Journal of Automotive Technology》2010,11(5):751-758
License plate location is a challenging task that is necessary for automatic vehicle identification. This paper presents a
new method for locating a license plate when its size and aspect ratio are highly variable. The proposed method begins with
an assumption that a license plate exists in a region where dense edges are located. We define an edge region as an area containing
rich edges. The edge regions are created by dilating vertical edges, and they are classified into one of four types: left
fragment type, right fragment type, whole type, and undefined type. The candidates for a license plate region are constructed
by merging edge regions. Knowing what type of edge region is being examined is useful in the merging process. Finally, we
verify whether each candidate contains a license plate or not by using the character arrangement information. The arrangement
pattern is determined by the size of connected components and by the vertical overlap or horizontal distance between two neighboring
components. Experimental results show that the proposed method gives robust results regardless of any variation in the size
and aspect ratio of license plates. 相似文献
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目前,车牌识别发挥在众多应用程序和许多技术已经提出。但是,他们中的大多数可以仅适用于单行车牌。在实际应用程序方案,也有现有的许多多行车牌。传统方法需要对双行车牌的原始输入图像。这是一个非常复杂场景中的难题。为了解决这个问题,我们建议一个端到端的神经网络为两个单行和双行车牌识别。是的原始输入车牌图像的分段。我们查看这些整个图像作为一个单位在要素映射后直接深度卷积神经网络。大量的实验表明我们的方法是有效的。 相似文献
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针对牌照字符目标与背景的差异性,提出1种基于数学形态学的牌照字符提取方法。该算法对输入图像进行相邻像素差分,保留纵向纹理;通过二值化和数学形态学处理,得到许多大小不同的连通域;计算各连通域的特征参数,利用牌照区域和背景区域对应的连通量的特征差别,实现有效抑制背景而保留牌照的目的。选择了1组有代表性的图像作为测试样本,验证了该算法的准确性和环境适应性。 相似文献