基于方向小波变换的边缘检测算法

提出了一种基于方向小波变换的边缘检测算法.本文详细介绍了方向小波变换的原理、基于此的图像边缘检测算法,比较了方向小波变换和传统小波变换、Canny算子在图像边缘检测的效果.实验结果表明,方向小波变换更符合图像的方向、纹理特征,因此更能反映图像的边缘信息,对传统的小波变换、Canny边缘检测算法有一定程度的改进.     

一种彩色PCB图像的边缘检测算法研究

在以图像处理技术为核心的PCB自动光学检测系统中,图像的边缘检测占有重要的地位,并且彩色图像提供的边缘信息更丰富.提出了一种检测彩色PCB图像边缘的方法.首先将彩色图像由RGB空间转换到HSI空间,然后应用基于中心样条滤波和4个模板方向的Sobel算子计算梯度幅值的改进Canny算子,分别对HSI的三分量检测其边缘,并...     

基于改进蚁群算法的图像边缘检测研究

针对基本蚁群算法对图像边缘检测效果不理想,提出了一种改进蚁群的图像边缘检测算法。通过改进蚂蚁转移规则和信息素更新策略,使得蚂蚁更具有多样性选择。实验仿真结果表明,该算法可以有效地检测出图像边缘,提高检测的效果。     

基于改进Canny算子的铁轨边缘检测方法

边缘检测是铁轨异物入侵检测的关键技术,针对铁轨图像边缘检测效果不佳的问题,设计了一种基于改进Canny算子的边缘检测算法.通过极值中值滤波平滑图像,提出加权系数梯度幅值和方向计算方法,并采用改进的迭代式阈值分割方法来确定Canny算子的最优高、低阈值,从而实现铁轨边缘的精确检测.对检测结果进行定性定量分析,结果表明,该方法提高了边缘检测定位精度,有较好的连续性、抗噪性能和清晰度.     

一种用于立体匹配的边缘提取改进算法

针对立体匹配中的边缘提取.本文提出一种简单而实用的改进方法.通过Canny算子检测最初的边缘.再利用几何信息选择关键点.根据关键点所确定的标记进行边缘连接,获得完整的边缘.该方法排除了孤立边缘,虚假边缘对边缘检测的影响,并通过引入直线分段法提取有用边缘.降低了算法的复杂度.实验结果表明,改进方法的边缘提取定位精确且连续性好.轮廓全面清晰.点、线特征突出,为立体匹配打下了良好的基础.     

蚁群算法在全方向M型心动图检测中的应用与研究

为了解决传统边缘检测算法对全方向M型心动图检测效果差的问题,根据基于蚁群算法边缘检测的思想,提出一种基于改进的蚁群算法的边缘检测算法。根据心动图间接来源于CT图的原理,一幅心动图中包含目标、背景、边界和噪声等内容,因此采用传统的边缘检测算法的效果并不理想。这里在传统蚁群算法边缘检测的基础上,根据心动图的特点,采取改进的转移规则和信息素更新策略,以提高检测精度和适应性。再逐步细化,使用蚂蚁算法进行详细的检测,得到最佳的运动曲线。实验结果表明,该算法可以获得精确的运动曲线,其结果能够比传统的方法获得更丰富更真实的心动图运动细节信息,为医生的诊断提供更多信息。     

多结构抗噪膨胀-腐蚀型数字灰度图像边缘检测的研究

传统的边缘检测方法对噪声敏感,抑制噪声能力差,经典的形态学边缘检测方法虽然具有较好的去噪能力,但不能反映全部的边缘特性.为此本文提出了一种改进的多结构抗噪膨胀腐蚀型数字灰度图像边缘检测算子.通过仿真结果比较,该算了在检测图像真实边缘和抗噪性能上均优于传统的边缘检测算子.     

一种改进的图像边缘检测方法——Weighted CHNN

文中提出了一种改进的CHNN方法,称为Weighted CHNN（加权的CHNN,简称WCHNN）方法.该方法在CHNN神经网络元的n个连接上施加权值,可以通过各种局部搜索、优化算法,使用指定的样本输入、样本输出等方法来训练该WCHNN网络从而确定各权值,使得WCHNN在保留了CHNN的优点的同时,还可以根据不同的样本输入输出图像来调节边缘检测的灵敏度,从而提高检测结果质量并避免检测结果中出现边缘过宽的情况.实验结果表明,训练后的WCHNN网络,比起CHNN有着更低的边缘检测错误率,并可检出原来CHNN方法漏检的边缘.     

基于标准化梯度的多尺度边缘检测方法

多尺度边缘检测中各个尺度中用来判定是否为边缘的阈值对结果有很大影响.在小波多尺度边缘检测中引入标准化梯度的方法,较好地解决了出现伪边缘和有意义的边缘损失的问题,使各尺度阈值的选取更具有稳健性,从而得到更稳健的多尺度边缘检测结果.最后通过实验证明算法的有效性.     

一种改进的Sobel边缘检测算法的设计及其FPGA实现

为了快速得到边缘更清晰、敏感度更高的实时边缘图像数据,提出了一种改进的Sobel边缘检测算法.对原始图像的边缘进行平滑滤波后,利用2个3×3模板对选定的二维图像中同样大小区域内的数据进行卷积,合并水平及垂直方向的导数得到该区域的梯度值,再通过添加的梯度方向模块对该区域进行4个方向的判断以帮助确定边缘,最后通过非极大值抑制及二值化处理确定图像边缘.将改进后的Sobel边缘检测算法在FPGA上进行了实现并证明了其有效性.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.