一种有效的车牌定位方法——数学形态学和字符边缘特征相结合的车牌定位方法

汽车车牌的定位是车牌自动识别系统中的关键环节。采用数学形态学和字符边缘特征相结合的方法对车牌进行定位,首先对车牌图像进行图像的预处理,然后利用数学形态学进行粗定位,最后利用字符边缘特征进行车牌的精确定位。从而实现了车牌图像的准确定位。     

基于数学形态学与投影法的车牌定位

车牌定位在车牌识别系统中具有关键的作用,定位结果的好坏决定着后续的车牌字符识别。针对数学形态学定位会产生多个伪车牌区域,当区域较多时定位不准的问题,提出一种数学形态学与投影法相结合的车牌定位方法。首先对车牌图像进行预处理;然后进行边缘检测、二值化,运用数学形态学处理获得候选车牌区域;最后对候选车牌进行行列扫描投影来提取准确的车牌区域。实验表明,该方法具有定位精度高,鲁棒性较好的特点。     

基于金字塔变换和形态学的车牌定位算法研究

车牌定位是车牌识别系统的关键技术之一。为了快速准确地定位车牌,文章提出一种改进的金字塔变换和数学形态学的车牌定位算法。首先通过金字塔变换进行预处理,增强图像的细节信息,减弱环境和光照等条件变化对车牌定位的影响;然后利用图像二值化和数学形态学技术形成包含车牌的若干候选区,在此基础上设计了一种"先周边后中心"的车牌提取算法;最终准确定位出车牌位置,提取出车牌图像。通过对不同地点、不同自然条件下采集的图像进行测试,得出定位准确率为99.2%、平均定位时间为0.309s,证明了该车牌定位算法准确可行,具有良好的性能。     

一种彩色汽车车牌的自动分割方法

汽车牌照的定位是一个公认的较难解决的图像分割问题,文章提出了一个综合多种特征的车牌分割算法;该算法首先利用颜色信息特征加强输入图像的车牌区域,然后基于车牌区域的灰度变化和纹理特征提出一种垂直边缘检测方法实现牌照与背景的进一步分离,使用数学形态学滤波和区域合并,最后运用投影法确定牌照区域;实验结果表明,该方法取得了良好的效果。     

基于灰度累积投影与边缘图像跳变统计的车牌定位方法的研究

针对交通检测系统中数码相机所拍摄到的图片,提出一种车牌定位方法:首先对图像进行二值化和边缘检测等预处理,然后根据边缘二值图中车牌区域的边缘特征,利用行扫描方法对图像进行灰度累积投影与边缘图像跳变统计,再根据车牌区域的字符纹理特征及灰度值特征确定车牌的水平位置.利用列扫描方法对图像进行灰度累积投影,用形态学的方法对细长线条的过滤,从而达到对车牌进行准确的垂直定位.实验表明,这种方法取得了较好的效果,具有较高的实用性.     

基于形态学原理的车牌定位方法

在智能交通系统中,车牌自动识别是一个重要的组成部分.本文展示了一个实时、有效的车牌识别方法.首先增强图像并利用车牌中字符的特点,用形态学的原理构成一系列算法,将汽车图像中车牌区域于其它部份分离,随后依据车牌的比例作一个掩模,利用形态学重构算法,在汽车图像中最终定位车牌并返回原图像分割出汽车牌照.实验证明这是一个非常有效的方法.     

基于Top-Hat预处理和小波能量分析的车牌定位算法

针对车牌定位不准的问题,提出一种新的数学形态学变换结合小波分析的车牌快速定位方法。该方法对Top-Hat变换图像二值化,然后分别在水平与垂直方向投影,在对投影信号进行一维小波分析的基础上,利用小波多分辨率特性结合车牌位置信息来缩小搜索范围,从而提高了定位精度和实时性。对多幅图像利用该算法进行车牌定位,平均定位时间0.125 s,与其他几种常见算法进行仿真试验比较表明,该算法具有较好的实时性和鲁棒性。     

改进的高低帽变换对固定阈值二值化算法的优化

由于车牌识别系统大多工作在复杂的光照环境中,如何解决不均匀光照对车牌图像的影响仍然是车牌识别领域的一个难题。数学形态学中高低帽变换的重要用途就是校正不均匀光照对图像的影响,但如果直接将其用于车牌图像的二值化处理,因为图像的灰度值变换不大导致部分边缘损失,不仅不利于确定良好的阈值,而且检测结果也不理想。利用高低帽算法的特点,首先用形态学膨胀算法调整结构元素尺度,改进传统高低帽变换的边缘检测算法,然后利用检测图像边缘熵确定权值进行融合,再对其进行固定阈值二值化处理。实验证明这一方法有效提升了车牌图像的边缘灰度,减小了光线不均对车牌图像造成的影响,增强了车牌识别的准确度。     

基于图像处理的车牌定位方法的研究

对智能交通系统的核心技术——汽车牌照识别技术进行了研究,在图像处理技术的基础上,着重研究了车牌区域定位技术,分析了目前有代表性的车牌定位方法,介绍了利用粒子图像测速关联PIV（Particle Image Velocimeter）算法原理,提出了一种采用车牌字符笔画2个边缘互相关值最大的方法进行车牌定位的算法,准确而快速地检出了车牌区域,为后续车牌字符识别打下了很好的基础。     

一种基于边缘特征的汽车牌照定位算法

车牌定位技术是汽车牌照识别系统中的一项关键技术 .基于视频检测模块所捕获的车辆图像的成像特点 ,采用反锯齿的方法对其进行优化 ,并根据车牌的边缘特征 ,提出了一种基于边缘图像频率变化特征的二次车牌定位算法 ,用于车牌的定位和提取 .实验表明 ,该定位算法快速、准确 ,具有较强的鲁棒性 .     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.