三维医学图像的混合噪声去除方法

针对医学图像在采集传输等过程中易受噪声污染,且目前多数去噪方法对混合噪声去噪效果不好,影响三维重构精度的问题,提出了基于自适应三维分数阶积分和中值滤波结合的混合噪声去除方法。首先介绍了几种传统方法在去除混合噪声中的不足,然后基于三维图像梯度信息提出了三维分数阶积分的自适应分数阶阶数,利用分数阶积分和中值滤波的各自优点,将两者结合对混合噪声去噪,并提出了基于混合去噪的边缘曲面追踪算法。实验结果和数据分析表明,提出的混合去噪方法能够从噪声污染的医学图像切片中追踪出高精度边缘曲面,与传统去噪方法相比,具有更好的去噪效果。     

椒盐噪声图像降噪算法设计

由于环境和设备的影响,图像往往受到不同程度的噪声干扰。为了有效地利用图像所包含的信息,通常需要对图像进行去噪处理。因此,图像去噪作为图像处理最基本的步骤,已经成为当前研究的重点内容之一。通过对现在常用的图像降噪算法的研究,选定自适应中值滤波对图像进行针对椒盐噪声的降噪,使用整体嵌套边缘检测（Holistically-Nested Edge Detection,HED）算法对图片进行边缘提取,辅助保留图像的边缘信息,使得图像的边缘信息得到更好的保留。     

基于三维轴距的图像去噪算法

图像去噪是图像处理邻域的重要课题,该文在3维直方图的基础上定义图像的3维轴距,分析无噪声及椒盐噪声影响下图像3维轴距的分布特点,提出基于3维轴距的去噪算法。算法首先对图像进行边沿扩展,再利用3维轴距来检测噪声,最后用非噪声中值滤波来消除噪声。仿真比较了3维轴距去噪算法与中值滤波、自适应开关中值、快速自适应均值滤波、修正方向加权中值滤波和自适应模糊开关中值滤波算法的去噪性能,结果证明该文算法的有效性。     

基于神经网络噪声检测的自适应中值滤波器

针对椒盐噪声污染图像的滤波问题,提出了一种基于前馈神经网络的噪声检测器。基于这种噪声检测方法,采用自适应中值滤波算法,依据像素点的不同属性采用不同的滤波策略。实验结果表明,该算法在有效去除椒盐噪声的同时更好地保留了图像的边缘和细节,是一种有效的图像去噪方法。     

融合梯度及分数阶积分算子的SVM滤波

为了在滤除椒盐噪声时更好的保护图像特征信息 ,利用分数阶积分算子、梯度信息和SVM 设计了一种滤波方法 FG-SVM。先设计PCNN噪点检测模型,将检测的噪点及信号点对应位置分别标记为1和0, 生成标记图像;然后根据标 记图像,在噪声图像上对每一个以信号点为中心的5×5区域,用中心 点周围的像素灰度信息、分数阶积分算子及梯度信 息构建训练样本,训练SVM获得去噪模型;再取以噪点为中心的5×5 区域构建测试样本,作为SVM去噪模型的输入来 估计区域中心的灰度值;最后用SVM的估计值取代噪点的灰度值,得到去噪图像。仿真试验 表明,分数阶积分阶次取 1.7时,能获得最好的去噪效果。对含噪 1%的Lena、Pepper及Camer.去噪,FG-SVM 的PSNR比MPCNN分别提高了[4.19,3.64]dB,且去噪图像的边缘细节清晰。     

基于噪声检测的自适应中值滤波算法

针对现有中值滤波算法对于高密度噪声图像以及纹理细腻图像的边缘处理能力欠佳的缺陷,提出一种基于噪声检测的自适应中值滤波算法.新算法根据噪声点与周围信息的关联程度将噪声点滤波值进行调整,从而更好的处理图像的细节部份.新算法中的自适应策略加强了滤波算法的去噪性能,使其对于含有任意噪声密度的图像也能很好的进行噪声滤除.通过仿真分析,新算法对于细节丰富的图像以及高密度噪声的图像滤波效果良好,有效的提高图像的峰值信噪比,其去噪效果相比其他方法更加优秀.     

基于分数阶微分算子与高斯曲率相结合的自适应图像去噪

文中提出分数阶微分算子和高斯曲率相结合的自适应图像去噪方法。将高斯曲率引入偏微分方程模型中,由图像梯度进行边缘检测,再结合高斯曲率和分数阶微分算子的性质,由图像的局部方差建立分数阶微分算子,构建基于分数阶微分算子的自适应图像去噪模型,进行自适应地扩散去噪。结果表明,新算法性能优异,内部信息保护更具完整性,有利于实际应用。     

基于盲估计和双边滤波的SAR图像稀疏降噪

合成孔径雷达（SAR）在成像过程中由于固有成像机制的缺陷导致图像被乘性噪声污染，图像噪声对后续目标检测识别等处理过程造成了阻碍。现有的去噪算法存在不能自适应估计噪声大小和对边缘保持效果不理想的问题，如何自适应处理不同噪声水平的图像是一个研究难点。提出一种基于盲估计和双边滤波的SAR图像稀疏去噪算法。首先利用双边滤波得到具有良好边缘保持特性的预处理图像；接着利用盲估计获取图像全域噪声水平，将其充当稀疏重建过程中的残差阈值；最后利用稀疏编码和字典学习算法，用尽可能少的原子信息来表示图像，达到图像去噪的目的。实验结果表明，结合了盲估计的稀疏重建算法不仅有效去除了图像噪声，使等效视数获得了显著提升，而且峰值信噪比和边缘保持指数也有良好的表现，有效保留了原图的细节纹理信息。     

基于自适应流形高维滤波的太赫兹图像滤波算法

针对太赫兹图像分辨率差,噪声严重和信噪比低等不足,提出了一种基于自适应流形高维滤波的太赫兹图像降噪算法。算法利用中值滤波滤除太赫兹图像的强噪声点,再利用自适应流形高维滤波去除图像中的大部分噪声,最后通过基于拉普拉斯高斯算子的边缘增强对二次滤波后的结果图像进行图像增强。实验结果表明,该算法对于太赫兹图像有良好的降噪效果,在滤除图像中噪声的同时,图像的边缘和细节部分也得到了较好的保留。     

一种基于PCNN的医学图像混合噪声滤波方法

根据脉冲耦合神经网络同步脉冲发放特性来定位脉冲噪声和高斯噪声点的位置,提出一种在该网络控制下,只对与噪声相关的像素进行均值计算以替代噪声像素的亚均值滤波算法,实现了图像的较强自适应滤波。计算机仿真实验结果表明,这种方法适应性强,在去除医学图像噪声的同时能很好地保留医学图像的细节和边缘信息,有利于改善医学图像质量、提高信息利用率和诊断的正确率。该方法的效果优于均值滤波、中值滤波、维纳滤波等去噪方法,是去除医学CT图像混合噪声的一种比较理想的方法。     

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.     

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.     

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.     

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.     

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.     

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.     

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