结合光流法与最近邻算法的运动目标检测

运动目标检测具有广泛的理论和现实意义,光流法是检测运动目标的重要方法之一。但是用于运动目标检测的光流算法却有着计算量大、处理复杂的问题。一种聚类分析算法和改进的LK光流法相结合检测方案可以很好地解决此类问题。对基于改进的LK光流法的运动目标检测算法进行了分析和仿真,再加以聚类分析使得检测出的运动目标更加准确。首先对图像序列进行采样与预处理,并利用LK光流法计算得出相邻帧图像的光流场,然后再利用最近邻聚类算法对得到的光流场进行处理,进而检测出图像中的运动目标,最后使用Matlab软件进行算法程序验证。通过实验可知,基于金字塔LK光流法与最近邻算法的运动目标检测方案可以更加有效地检测出运动物体。     

一种新型快速运动目标检测算法

为了克服光流法计算量大和亮度不连续性引起的运动估计误差,提出一种基于改进帧差法和改进光流法相结合的快速运动目标检测算法.通过改进帧差法,精确获取运动目标区域.利用改进的光流法,在光亮度不连续的情况下,准确地提取运动目标区域特征点的光流,并对光流矢量采用阈值标注,进而检测出运动目标.实验结果表明:该目标检测算法鲁棒性强,计算量小.     

基于光流技术和滤波器方法的多尺度微运动测量

将光流技术和多尺度方法相结合,提出了一种基于光流技术和梯度滤波器的多尺度高精度微运动测量方法.该方法将微运动测量看成是光流的计算,采用滤波器方法计算图像的梯度,并利用多尺度方法将较大像素的图像运动转化为多个小像素的图像运动进行估计,从而提高运动估计精度.该方法用于测量2个像素附近的微陀螺图像运动时,最大测量偏差小于0.008个像素.实验模拟结果表明,这种采用光流技术和多尺度相结合的方法能够实现高精度的微运动测量.     

基于机器视觉的工程机械行走速度测量方法

为实现工程机械实际行走速度的实时在线检测,通过建立一种基于机器视觉的间接测速模型,把摄像机安装在行走的工程机械车辆上,并对摄像机进行标定确定出摄像机内外参数;在工程机械实际行走过程中实时采集前方路面的连续帧图像进行光流分析,根据运动主方向原理来建立光流运动方向;实验采用一种基于改进的金字塔式Lucas-Kanade光流算法计算出路面连续帧图像的光流速度;统计出所有图像间的平均光流速度后,根据标定所得的摄像机参数、图像坐标与世界坐标的关系计算出实际行驶速度。测试结果与实际速度比较得出误差为1.45%,结果表明该方法能精确反映工程机械的实际行走速度。     

一种基于改进运动历史图像和支持向量机的行为识别算法

针对传统运动历史图像难以区分相似运动的缺陷,提出了一种基于改进运动历史图像和支持向量机的行为识别方法。首先提取视频帧的前景运动目标并标记出其外接矩形框,计算矩形区域内各像素的光流矢量;然后设定运动历史图像中前景像素点的灰度值为该像素点的光流长度叠加一定权重的历史灰度,而背景像素点的灰度值则按一定比例进行衰减;最后从运动历史图像中提取Hu矩为特征向量,输入支持向量机进行分类,从而完成人体行为识别。在KTH数据集的实验结果表明,所提算法能够满足实时性要求,识别率可达99%。     

融合改进帧差和边缘提取算法的运动目标检测

针对帧差算法检测运动目标存在的目标边缘缺失和空洞的问题,提出一种将改进帧差和基于改进Canny算子的运动目标边缘提取方法相融合的运动目标检测算法。首先,使用帧差法快速检测变化区域,并通过面积阈值判断是否进行当前帧的检测以提高算法实时性;其次,在运动目标边缘提取中,提出一种基于改进Canny算子的运动目标边缘提取方法提取当前帧运动目标边缘,以解决检测目标边缘缺失的问题;最后,将改进的三帧差分法提取运动目标像素点填充目标边缘图像,以解决检测目标内部空洞的问题。对比实验结果表明,该融合算法对视频中的运动目标能以较高的准确度和完整度实现运动目标的高效检测。     

基于像素流的视频彩色化

针对利用传统光流传递关键帧颜色信息的视频彩色化方法计 算耗时问题, 以及全局传递颜色的视频彩色化方法导致欠饱和度问题, 提出基于像素流的视频彩色化方法. 首先, 将参考帧与目标帧转换到 Lab 颜色空间中, 利用其亮度通道通过一个深度学习网络得到像素流, 该像素流中的数值指示了目标帧的颜色在参考帧中的位置; 然后, 利用该像素流对参考帧颜色通道进行双线性插值得到目标帧颜色通道; 最后, 将得到的颜色通道与目标帧亮度通道组合得到最终的彩色化图像. 实验结果表明: 该方法得到的彩色化图像能够保持参考帧颜色的饱和度且边缘颜色清晰, 具有更高的峰值信噪比; 运算速度较基于传统光流彩色化方法大大提高.     

一种基于多项式插值改进的亚像素细分算法

介绍了一种基于多项式插值法的改进的亚像素细分算法及相应计算模板和公式，并对算法的误差进行了分析。本算法应用在经典Sobel算子基础上构造出的方向模板，对灰度图像进行处理，得到梯度图像，然后在梯度图像上沿目标边缘的梯度方向进行多项式插值法亚像素细分计算，对目标边缘进行亚像素精确定位。实例说明本算法是可行的。     

超像素梯度流与元胞机融合的视频显著图检测

使用静态空间特征通常无法得到准确的视频显著性目标对象,提出了超像素梯度流场与元胞自动机融合的视频图像显著性检测方法。首先,使用SLIC方法将视频帧分割成超像素,在超像素级上运用光流梯度和颜色梯度生成一个时空梯度函数,由时空梯度得到新的梯度流场值,将视频中运动信息充分利用起来;其次,在视频帧超像素图像上使用卷积神经网络得到其深度特征,通过元胞自动机使这些深度特征依自定义规则更新出粗略显著图,然后将梯度流场显著图与元胞自动机粗略显著图融合得到最终的显著图;最后,在ViSal数据集上、采用5种评估指标、与现有的4种方法进行对比实验,结果表明本文方法在动态视频图像显著性检测中有好的表现。     

大背景噪声下动目标实时检测方法研究

提出用帧间方块编码差值法和邻域综合法提取运动目标．第一种方法是把当前帧方块的二值图像像素编码值与前帧对应的二值图像像素编码值求差值，由差值检测运动目标；第二种方法是检测２×２方块内各像素的帧差值符号位和帧差绝对值，由二者判别是否运动像素．与普通帧差法相比，提高了抗噪度，改善了运动目标的边缘特性，减少了硬件量．检测算法可以以视频速率工作．实验结果表明，所提出的检测方法是有效的．     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。