采用二次定位的车牌图像定位算法研究

提出了一种二次定位的车牌图像定位方法.在第一次定位中首先对车辆图像进行灰度化、边缘检测及直线检测处理,根据车牌区域的特征初步找出包含车牌边框的车牌图像区域;再根据车牌边框对车牌图像进行倾斜校正;在此基础上,对车牌图像采用投影法进行二次定位,最终获得精确的车牌区域.测试证明,提出的二次定位方法能够适应不同背景,对光照、环境及车牌种类不敏感,得到的车牌图像不会包含车牌边框等无用的信息,为后续的车牌字符识别打下良好的基础.     

基于数学形态学和投影法的车牌定位方法

在车牌定位系统中,针对图像中存在的复杂背景、车辆自身的车灯或标志这些因素的影响,提出了车牌初步定位和精确定位的方法.首先,对车牌图像进行灰度化、灰度拉伸、边缘检测后,运用数学形态学运算和车牌自身的宽高比例初步定位出车牌区域.然后,运用投影法分别进行水平方向和垂直方向的定位,得到准确的车牌区域.该方法能够很好地排除干扰因素,精确定位出车牌.     

一种新的二值化方法在车牌检测中的应用

车牌定位过程中二值化方法的选择尤为重要,何时二值化以及选取何种二值化方法对检测结果的影响明显。考虑到车牌区域有着丰富的边缘信息,车牌区域的亮度以及区域标准差,能给二值化阈值提供有价值参考信息,文中根据车牌的特征提出了一种新的自适应二值化算法,并采用区域融合及连通域计算方法提取车牌。实验证明,此二值化算法对图像灰度变化、...     

基于多尺度小波边缘检测的车牌定位研究

车辆牌照的准确定位是车牌识别系统中的关键步骤,利用车牌区域丰富的边缘和纹理信息以及车牌自身的特征,提出一种基于多尺度小波边缘检测的车牌定位方法.该方法能够更好地解决在复杂背景和复杂光照下的车牌定位.首先用图像增强和多尺度小波算子提取出车牌图像的边缘,然后利用数学形态学和连通区域标记的方法对车牌进行初步特征提取去除伪车牌区域,最后采用水平垂直投影法进行车牌的精确定位.实验结果表明,该方法能够实现车牌的快速准确定位,对复杂背景下的车牌具有很好的鲁棒性和实时性.     

一种复杂环境中的车牌定位算法

提出了一种结合车牌区域边缘特征和梯度方向特征的新型车牌定位算法,该算法将车牌图像变换为灰度图像后,首先利用Sobel算子和Gradienffaces方法分别获取车牌图像的垂直边缘图像和梯度方向图像,然后根据边缘长度、边缘点密度去除垂直边缘图像中的干扰,并根据梯度方向图像中的梯度方向消除更多的干扰边缘,最后利用一个矩形窗扫描边缘图像完成车牌区域的定位和分割.实验结果表明,该方法的定位准确度可达93.7％,同时对复杂背景或弱光环境下的车牌图像具有很好的鲁棒性.     

基于Matlab的车辆牌照图像预处理的研究

车牌图像预处理及定位是车牌识别系统的一部分,是实现车辆牌号最终分割识别的前提。文中以实现车牌区域的定位为目的,运用Matlab图像处理工具箱对采集到的原始车牌图像进行彩色图像灰度化、二值化、边缘检测、数学形态学及滤波等预处理操作。实验表明,采用的预处理操作能够有效地定位出车牌位置,具有很好的鲁棒性。     

复杂车辆图像中的车牌定位

针对复杂背景的车牌定位问题,提出了一种综合形态、颜色、投影等多种特征的车牌定位算法.基于车牌区域边缘信息丰富的特点,首先利用边缘检测和数学形态学方法定位候选车牌区域,并消除噪声干扰;然后根据质心所在位置对候选区域进行由低到高的排序,并通过颜色识别作进一步筛选,以排除车灯等区域的干扰;最后采用投影法及谷值分析对截取出的缺损车牌进行补全,从而得到准确的车牌位置.实验结果表明,算法的效率与精度与车辆图像的清晰度、曝光度及车牌大小等因素有关,与传统车牌定位算法相比,效率和精度分别提高了15%和20%以上.     

一种基于图像处理和投影的车牌定位方法

为了提高车牌的定位率和准确性,通过对车牌特征的研究,提出一种采用颜色特征、图像处理和投影结合的定位方法。首先利用车牌的颜色特征将车牌可能区域从整幅图像中确定,再利用水平移差扫描,边缘检测对图像进行处理,并利用投影以及车牌的长宽比例相结合的方法,确定车牌具体位置。结果表明,此方法对蓝底白字车牌定位较准确,并且具有一定的鲁棒性和实时性。     

复杂背景下的车牌自动分割方法

车牌分割是汽车牌照自动识别的基础。本文针对含有车牌的灰度图像，利用车牌字符具有明显垂直纹理的特征．提出了一种适合字符纹理特征的边缘检测方法，获取垂直边缘图。根据车牌固有的特征，运用改进的投影算法确定车牌区域。文中详细给出了车牌分割步骤。实验结果表明，在复杂的背景下，该方法能够快速有效地实现车牌自动分割。     

基于灰度分布和字符紧密性特征的车牌定位方法

根据车牌区域的灰度分布特征,提出一种定位车牌区域的新方法.该方法先利用车牌区域灰度分布特征,对车辆图片进行粗定位并得到车牌上下边界;再根据车牌区域字符紧密性特征,利用垂直投影方法初步得到车牌的左右边界,最后根据字符宽度和间距进一步修正车牌的左右边界.经实验证明,该方法具有在复杂背景下适应性好、抗干扰、实时性好、定位精确等特点.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks