激光主动成像图像边缘检测算法研究

针对传统Canny边缘检测算法存在的不足,结合激光主动成像末制导的实际特点,提出了一种改进的Canny边缘检测算法。该算法在Canny边缘检测算法的基础上,采用同态滤波和提升小波变换级联的方法代替传统的高斯滤波器;采用3×3邻域的权值梯度计算方法代替原有的2×2邻域差分运算;利用类间方差最大值和梯度幅值直方图来进行高低阈值的自适应取值,使算法可根据图像自身特点选择最合适的阈值。实验证明:该算法提升了传统Canny算子的抗干扰能力和鲁棒性,能够较好地保存边缘信息,准确检测出激光主动成像图像边缘,具有较强的自适应性。     

一种基于改进Canny的边缘检测算法

鉴于传统Canny边缘检测算法在高斯滤波方差和高低阈值选取上需要人工干预,不具备自适应能力,以及其在梯度计算上的缺陷。提出了一种改进的Canny边缘检测算法。改进算法使用自适应平滑滤波代替高斯滤波,在平滑图像的同时锐化了边缘;使用水平、垂直、45°和135°四个方向梯度模板计算图像梯度,改善了传统Canny算法在计算梯度时对噪声的敏感性;引进Otsu算法自适应地根据图像灰度生成高低阈值,避免了人为设定高低阈值的难题。实验结果表明,改进算法在检测到更多边缘细节的同时,也具备较强的自适应性。特别地,在噪声环境中,改进算法比传统Canny算法检测效果更优。     

基于改进Canny算子的图像边缘检测方法

针对传统Canny边缘检测算法采用高斯滤波处理图像不能有效消除椒盐噪声的问题,提出改进Canny算子用于检测图像边缘.首先利用双滤波设计-融合自适应模糊中值滤波和双边滤波去除图像椒盐噪声,降低图像噪声同时保证图像边缘.然后在研究过程中遇到边缘检测人工阈值选取自适应不足的问题,采用最大类间方差(Otsu)算法计算得到高低...     

基于类间方差的图像Canny边缘提取改进

到目前为止,在边缘检测方面,Canny算子因为它优良的边缘检测特性,应用在很多方面。然而它也有局限性,传统Canny算子高低阈值是通过人工凭借经验来选取,且低阈值固定是高阈值的一半,这就使得它在一些特殊领域无法应用,且实际中图像易受光照、杂散光以及其他各种噪声的干扰。因此针对传统Canny算子阈值确定的困难性,针对性地提出了利用双重Otsu方法确定高低阈值的方法,此方法利用两次Otsu方法分别确定高阈值和低阈值。     

太赫兹成像三维块匹配自适应Canny边缘检测算法

针对传统Canny算子在滤波时会模糊边缘且需要人工设置高低阈值的缺点，提出了一种基于三维块匹配的改进自适应阈值Canny边缘检测算法，并用于太赫兹三维层析成像。该算法一方面对滤波方法进行了改进，用三维块匹配(BM3D)滤波算法结合引导滤波算法代替高斯滤波算法以减少图像边缘信息的丢失；另一方面，针对传统人工设定阈值的不确定性，将梯度图进行块匹配后对三维图像块组使用最大类间方差法(OTSU)以自适应确定高低阈值。最后利用该算法对含有噪声的图像进行边缘检测处理，发现在高斯噪声方差为20时滤波后的峰值信噪比(PSNR)从22.202提升至27.151，验证了该算法去除噪声的有效性。三维块匹配改进自适应阈值Canny边缘检测算法(BM-OTSU-Canny)减少了错误边缘的数量，同时保留了连接性较好的边缘点，改善了边缘细节信息的提取效果。     

基于改进Canny算子的垃圾图像边缘检测

为提高垃圾识别分类的准确率,文中在垃圾图像预处理过程中提出了一种基于改进Canny算子的垃圾图像边缘检测方法。该方法从传统Canny算子滤波方式、梯度方向及阈值自适应3个角度实现了垃圾图像边缘检测的优化。针对Canny算子高斯滤波仅适用于高斯噪声和边缘细节易丢失的问题,采用改进的梯度倒数加权法进行滤波。针对Canny算子易检测出伪边缘的问题,通过在计算图像梯度方向的过程中增加方向梯度模板实现了边缘的精确化。同时采用最小误差法解决人工设定阈值的局限性,实现阈值自适应。实验结果表明,该方法在去噪性能和边缘细节两方面得到了改进,获得了更好的边缘检测效果,为后续垃圾图像的识别分类提供了技术保障。     

基于图像处理技术的轮毂智能检测系统

为了实现轮毂关键几何参数的自动测量,基于图像处理技术研发轮毂智能检测系统。采用黑白高清CCD工业相机采集图像数据。利用Canny算子算法提取轮毂孔径边缘信息。根据轮毂图像特点,对传统Canny算子算法的滤波算法运用双边滤波和图像二值化方法进行改进。为了提高Canny算法的适用性,提出了一种自动计算阈值的方法。基于最小二乘法拟合轮毂孔径边缘,从而获取轮毂孔径大小的尺寸信息和圆心相对距离的位置信息。通过实验测量计算,轮毂孔径的尺寸和位置测量满足工业现场精度要求,实现了轮毂关键几何信息的自动测量。     

改进的Canny实时边缘检测算法在FPGA上的实现

针对高斯滤波会使图像过度平滑及高低阈值选取的主观性影响传统的Canny边缘检测效果,提出一种基于改进Canny算子的边缘检测方法.该方法采用了改进的中值滤波,且依据图像的幅值梯度直方图特性得到自适应的高低阈值,再结合FPGA(现场可编程门阵列)高速并行处理数据和多级流水的特点,设计了一个基于硬件平台的实时边缘检测系统....     

一种基于自适应Canny算子的舰船红外图像边缘检测方法

提出了一种用于舰船红外图像边缘检测的自适应Canny算子边缘检测方法。先利用图像的局部最大标准差值为参考值设定高斯滤波尺度参数,然后采用基于梯度幅度直方图的类间方差最大法计算Canny算子的高低闽值,从而实现边缘的自动检测。实验结果表明,采用该方法检测出的舰船边缘清晰连续,噪声较少,优于传统的Canny算子边缘检测方法,并且具有很好的工程适用性。     

基于改进Prewitt算子的最佳阈值选择

边缘作为图像的一种基本特征,在图像识别、图像分割等领域中有着广泛的应用。文中在传统的Prewitt算子改进的基础上,提出利用边缘的最大后验概率估计,找出边缘检测的最佳阈值。并将实验结果与Sobel,Canny等算子进行了对比。结果显示,文中算法能检测出最佳阈值。     

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.     

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.     

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.     

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.     

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.