首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
为解决前方车辆识别过程中的实时性问题,提出了一种基于车牌检测的前方车辆识别方法。首先,利用图像中的路面或车道线等细节提取感兴趣区域。其次,利用HSV( Hue-Saturation-Value) 色彩空间转换与矩形图像检测从感兴趣区域中过滤光照变化,阴影和杂乱背景,从而检测出车辆的车牌信息。同时,在初次检测失败的情况下进行二次定位和验证。最后,利用检测出的车牌信息识别前方车辆。该方法在自建与公共数据库视频上进行评估。实验结果表明,识别率超过90% ,并且具有较高的实时性,证明了该方法的有效性。  相似文献   

2.
基于视频图像测量隧道行车的速度,重点是检测车辆在视频图像序列中的位移,现有的位移测量方法大多采用特征匹配法和车牌定位法,两种方法都是提取车辆运动的特征向量来判断车辆的总体位移,有一定的局限性。本文考虑到傅里叶变换具有全局特性和相移特性,提出了一种将图像虚拟检测线灰度均值测量、傅里叶变换、相位相关和数字图像处理相结合的方法,来检测运动车辆及其在视频图像序列中的位移,再将位移量应用于摄像机中标定,计算隧道行车的速度,以提高车速检测的准确性和实时性。  相似文献   

3.
由于当前已有方法未能对车牌照进行降维处理,导致车牌照识别结果不准确,为此,提出一种基于Relief算法的智能车辆牌照模糊识别方法。采用Relief算法计算不同车牌图像特征的权重系数,对特征集进行降维处理。通过序列视频图像对智能车牌进行增强处理,利用全卷积网络对车牌照显著区域进行检测,粗略提取图像中的显著区域,使用滑动窗方法对候选区域车牌进行精准检测,定位车牌准确位置,加入字符的上下文信息,对字符进行精确检测和识别,最终实现智能车辆牌照模糊识别。仿真实验结果表明,所提方法可获取高精度的车牌照识别结果。  相似文献   

4.
关于高速公路收费系统车牌识别技术的研究   总被引:1,自引:0,他引:1  
王吉武  程琼 《科技信息》2010,(21):J0034-J0035,J0067
车牌识别是指通过计算机视觉、图像处理与模式识别等方法从车辆图像中提取车牌字符信息。从而确定车辆身份的技术。车牌识别分为车牌定位、字符分割、字符识别三大部分。车牌定位是一个难题:车牌区域在整幅图像中所占比例很小,车牌的颜色、大小、位置也不确定,并且定位算法要能够克服不同光照和复杂背景的影响,还要兼顾准确性和实时性,因此快速准确的定位车牌是比较困难的。本文通过车牌的纹理和颜色特征采用粗定位和细定位相结合的方法进行识别。  相似文献   

5.
刘伟  刘广文 《科技资讯》2014,12(24):26-26
车牌自动识别系统在实现智能交通系统方面发挥着重要作用,整个系统包括车牌定位、字符分割和字符识别三部分.本设计先确定车牌在获取图像中的具体位置,从而把车辆牌照定位出来,进而对车牌用局部投影的方法进行字符分割,最后采用模板匹配法进行车牌字符的识别.本文提出的方法具有实时采集视频图像,车牌定位准确,分割及识别效率高的优点.  相似文献   

6.
针对目前国内车牌定位系统易受背景干扰和定位准确率有待提高等问题,基于图像分解方法和DM6437DSP硬件平台,设计了一种嵌入式车牌定位系统.通过CCD摄像机和TVP5146视频解码芯片完成图像信息的采集,DM6437实现算法处理和数据传输等任务,并引入图像分解改进车牌定位算法.实验结果表明,图像分解方法能够有效去除车辆图像背景中的无用信息,进而提高车牌定位的准确率.基于DSP硬件平台的定位系统体积小,运行稳定,有较高的应用推广价值.  相似文献   

7.
为了满足南京长江三桥的技术状态评估和预测的需求,基于该桥收费站7年的称重数据库和桥面监控视频资料,根据不同的轴组类型对日常运营的主要车辆进行了车型划分.采用参数估计和非参数估计方法,建立了车辆质量、轴距、车型、轴重等车辆荷载模型中相关参数的数学模型.然后,基于泊松过程理论、Markov过程理论和车辆跟驰模型,对车辆荷载模型中的车速、车辆到达时刻等时变参数进行随机模拟.研究结果表明:多数车型质量分布为多峰分布,宜采用核密度估计法确定其统计模型;生成随机车辆时,需考虑车辆质量与车速、轴重等参数的相关性;采用M CM C法模拟得到的随机车辆车型分布近似于桥梁实际运营中的车型分布.  相似文献   

8.
针对车牌识别系统中,由于光照变化、背景复杂、车牌褪色或相对摄像机位置不同带来的图像倾斜等原因,导致车辆图像质量不高,影响车牌定位和识别。基于优化组合数学形态学基本运算,结合灰度信息离散化对车牌初定位,再利用先验知识,对车牌进行精确定位,最后采用两点法对倾斜的车牌图像进行检测和校正。实验结果表明,得出的定位和倾斜校正方法简单、快速,且具有较好的稳定性。  相似文献   

9.
高速公路收费系统图像识别技术的研究   总被引:1,自引:0,他引:1  
吴亚光 《科技信息》2009,(10):170-170
本论文主要完成对于车辆牌照的图像识别,车辆牌照的识别是基于图像分割和图像识剐理论,对含有车辆号牌的图像进行分析处理,从而确定牌照在图像中的位置,并进一步提取和识别出文本字符。识别步骤概括为:车牌定位、车牌提取、字符识别。  相似文献   

10.
一种基于车牌特征信息的车牌识别方法   总被引:18,自引:3,他引:18  
提出一种基于车牌特征信息分析的车牌识别方法,它充分利用车牌定位和字符分割过程中得到的信息对车牌识别过程进行反馈,将二值化、车牌定位和字符分割紧密结合,注重车牌与车辆背景图像分离特征,以连通域分析为字符分割特点,结合局部二值化算法,提高正确率。实际应用结果表明,本方法具有很强的环境适应性和鲁棒性。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
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.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
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。  相似文献   

17.
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.  相似文献   

18.
19.
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  相似文献   

20.
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  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号