一种双边核函数的新Harris角点检测算法

针对目前Harris算法存在的对噪声敏感和检测率不高的不足,提出一种双边核函数的新Harris角点检测算法.算法首先采用双边滤波器来代替原有的高斯低通滤波器,来增强算法的鲁棒性;接着采用多尺度分解来建立真实角点和伪角点的分割阈值.实验结果表明,提出的算法能精确地检测图像角点.     

一种新的Harris多尺度角点检测

Harris角点检测是一种经典的角点检测算法,但不具有尺度变化特性。该文把多分辨分析的思想引入到该算法中,构造了基于小波变换的灰度强度变化公式,并得到了具有尺度变换特性的自相关矩阵,从而构建了一种新的基于小波变换的Harris多尺度角点检测算法。这样,使得新的角点检测可以在不同的尺度下获取角点,并克服了单一尺度的Harris角点检测可能存在的角点信息丢失、角点位置偏移和易受噪而提取出伪角点等问题。通过对比实验,新算法明显地提高了图像角点检测性能。     

基于多尺度二阶广义高斯方向导数滤波器角点检测算法

检测性能良好的角点检测算法能够应对多幅图像中的不同特征及变化,且能够很好的检测图像中的不同或相似特征。二阶各向异性高斯方向导数(SOGGDD)可以很好的提取不同方向的图像信息,并且可以很好的应对噪声干扰,研究了,将不同尺度的图像信息和二阶各向异性高斯方向导数结合提出了一种基于多尺度二阶广义高斯方向导数滤波器的角点检测算法,该算法可以有效提高检测的平均重复性,有效应对不同条件的变化。实验采用了标准数据库和角点检测文献中的28张场景图进行比较。通过对该算法和多尺度Gabor角点检测算法进行平均重复性的对比,实验表明提出的算法具有更好的角点检测性能。     

基于图像尺度空间的几何不变特征点提取算法

图像特征点的提取是实现抗几何攻击数字水印算法的重要步骤，所提取的特征点是否鲁棒，将直接影响抗几何攻击水印的鲁棒性．Harris—Laplace角点检测方法是一种多尺度抗几何攻击角点提取方法，但计算比较复杂．将Harris．Laplace角点检测方法进行改进，把直接分析图像局部灰度值的角点提取方法与图象尺度空间的思想相结合，并兼顾多尺度的不同权值，则既可以保证角点抵抗一般几何攻击的鲁棒性，又减少计算复杂度的，根据此思路提出了加权平均Harris-Laplace角点检测方法来提取特征点．实验结果表明，该算法提取的图像特征点不仅具有很好的抵抗图像裁剪、几何缩放能力，而且计算复杂度明显低于相同重复检测率的Harris—Laplace角点检测算法．     

基于FPGA的图像多尺度特征点提取及匹配

对于图像的多尺度特征点提取及匹配存在提取特征有限、算法复杂度高、处理速度慢的问题,提出了一种利用多尺度Harris角点方法提取图像中物体边界特征点,采用二维高斯拉普拉斯算子检测图像斑点信号,并基于SIFT特征描绘子计算特征描绘子相似度来完成匹配的方法.该方法充分利用FPGA的并行性特点,通过降低多尺度Harris角点检测、斑点提取和SIFT特征描绘子生成算法的复杂度,在FPGA中实现了图像多尺度特征点的快速提取及匹配.通过对多组图片进行对比测试验证,该方法相对于软件实现方法具有处理速度快,而图像主要特征点不丢失的特点.     

改进的Harris算法在海洋遥感图像处理中的应用

研究HY-1B卫星水色图像数据时需要先对水域进行定位,一般采用轮廓明显的海岸线来辅助附近海域的定位。为了克服基于传统Harris角点检测算法带来的漏检、定位精度差等问题,提出一种改进Harris角点检测算法。在双边滤波预处理图像后引入多尺度空间表示,最终对候选角点集进行分组检测选取出最小尺度下的角点作为最佳角点。实验结果表明,改进的算法提高了角点检测率并且减少了冗余角点数量,优于多尺度Harris算法和Harris-Laplace算法。     

一种基于支持向量机的角点检测算法

支持向量机应用于文本分类、手写数字识别、基因表达等许多领域,由于Harris角点检测算子对噪声点非常敏感,本文在文献[3]的基础上提出Harris算子和支持向量机相结合的方法来进行角点检测.首先利用Harris角点检测算法对两幅以上的无噪声图像提取角点,然后将提取的角点作为支持向量机的训练样本.构造支持向最机,最后利用...     

一种分块的基于Harris角点检测的图像配准方法

传统的Harris角点检测选用全局的阈值并且不具有尺度不变性,对于较大的图像会导致检测的角点分布不均、错检等问题,为此提出一种新的基于多尺度的Harris角点检测的图像配准方法。首先将图像分块,并对其进行相应排序,根据局部阈值来提取Harris角点,然后根据图像特征点的最邻近和次邻近距离之比来确定初始匹配,最后利用特征点附近的灰度信息来实现进一步的配准。实验证明此方法使得图像配准精度和配准效率得到了极大地提高。     

分块的基于Harris角点检测的图像配准方法

传统的Harris角点检测选用全局的阈值且不具有尺度不变性,对于较大的图像会导致检测的角点分布不均、错检等问题,为此提出一种新的基于多尺度的Harris角点检测的图像配准方法.首先将图像分块,并对其进行相应排序,根据局部阈值来提取Harris角点,然后根据图像特征点的最邻近和次邻近距离之比来确定初始匹配,最后利用特征点附近的灰度信息来实现进一步的配准.实验证明该方法使得图像配准精度和配准效率得到了极大提高.     

基于图像分块的Harris-SIFT特征匹配算法

应用Harris角点和SIFT图像局部特征定量化数据描述的互补优势,提出了图像分块Harris-SIFT特征匹配方法。将原图像分割成子图像块,根据子块的可变阈值检测多尺度Harris角点,并对其进行迭代精化,使其收敛到真值,然后生成定量化的特征矢量。匹配应用双向最近邻算法并用RANSAC去除误匹配。通过仿真验证,这种方法增强了角点提取的鲁棒性,提高了匹配速度和精度。     

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.