基于潜在半径优化策略的数字图像抠图算法

针对目标图像利用导向滤波算法进行图像抠图时参数需要根据不同图像进行人为设定的问题,提出了一种利用隐藏的支持向量机LSVM(latent support vector machine)自动设定参数的潜在半径优化的数字图像抠图算法.该方法首先是应用LSVM潜在性的思想,利用已知数据库模板训练输入目标图像的样本集,再利用样本集将导向图像和二值图像以不同半径进行分块并进行判定,确定半径值,从而能够自动产生合理参数.最后利用导向滤波器对图像进行抠图,从而优化抠图算法,最终实现抠图算法的智能化和灵活化.     

采用精确抠图的单幅自然图像背景虚化合成方法

针对小光圈镜头下的单幅自然图像背景虚化问题,提出一种基于精确抠图的单幅自然图像背景虚化合成方法.首先,利用GrabCut算法对单幅自然图像的前景对象进行初始抠图;其次,采用基于局部二值模式算子的颜色恒常性算法提取图像纹理,并对初始抠图实现精确割图;然后,通过双边滤波虚化背景部分;最后,将精确分割后的前景部分与虚化后的背景部分合成.仿真结果表明：文中算法可以获得高质量的分割和视觉自然的背景虚化效果.     

结合Kinect深度图的快速视频抠图算法

现有视频抠图算法主要存在人机交互繁琐、计算复杂度高的问题,为此,该文提出了一种利用Kinect深度图的新的快速视频抠图算法。首先结合彩色图信息改进区域生长算法,估计出三色图(原始图像被3种颜色标记出前景、背景和未知区域)以避免深度图中遮挡区域的影响。其次,提出前景和背景样本点集二次筛选机制,保证估计精度的同时大幅降低计算复杂度。最后,采用深度、彩色和置信度图对抠图结果进行加权滤波,减少不透明度图像中低置信度的像素点和不平滑区域。实验结果证明了该算法精度高、速度快且交互简单。     

基于马氏距离和模糊C均值聚类的抠图算法与应用

基于马氏距离和模糊C均值聚类算法提出了一种数字彩色图像抠图算法.该算法首先对彩色图像像素的红绿蓝三种彩色分量进行正则化处理;然后在正则化图像背景中选取适当的掩膜作为样本集,计算各像素与样本集之间的马氏距离;再利用模糊C均值聚类算法对计算出的马氏距离进行分类;最后利用填洞操作提高抠图质量.对八幅彩色数字图像进行对比实验,结果显示本算法可以自动抠图,且结果优于马氏距离算法、Grow-Cut算法和正则化线性回归算法的相应抠图效果.     

电子商务网站中二维服装搭配展示设计与实现

针对服装电子商务网站二维展示中服装素材图像制作的需求,提出一种基于图像处理技术的服装抠图和服装搭配展示方法.该方法先采用颜色聚类分析等算法对模特着装图进行二值化处理,获取服装图像掩膜,进而对模特图像与服装素材图像按相应的规则进行叠加处理,以实现服装搭配效果展示.原型系统测试表明,该系统运行响应速度较快,能够实现服装抠图和叠加展示功能.     

拼接法纹理合成中的结构特征匹配

提出一种新的纹理合成技术,该方法对样本纹理图像进行采样,逐块合成纹理图像.在寻找最优候选匹配块时改变以往算法中仅匹配颜色相似度的做法,加入结构信息,提高了块边界结构的相似度.用该算法选择的最优匹配块更符合人的视觉特性,合成图像接缝区域的过渡更为流畅,结构单元的完整性明显优于原有方法.实验结果表明,该算法对结构性强的纹理具有良好的合成效果.     

基于多特征融合的混凝土结构表面病害图像分类算法

为提升混凝土表面开裂、露筋锈蚀和损伤3类病害图像分类效率与准确性,减少人工成本,提出了基于多特征融合的混凝土结构表面病害图像分类算法。该算法通过提取混凝土表面病害图像的纹理特征、灰度直方图特征、颜色特征,以支持向量机(SVM)为分类器,分别训练3类特征的病害图像分类模型,采用特征权重算法估计各个特征的权重系数,借助分类模型与权重系数估计病害图像类别划分的可信度值,根据最小误差原则将病害图像判定为可信度值最大的类别。设计了7组覆盖上述图像特征的特征融合方案,以2 400张病害图片为样本,训练了3种单一特征和4种多特征病害图像分类模型,并测试算法的准确性。结果表明:总体上,多特征融合分类模型对于混凝土表面病害图像分类准确率高于单一特征分类模型;基于多项式核函数,灰度+颜色+纹理特征融合分类模型分类效果最佳,平均分类准确率达到84%,较单一特征分类模型提升了7%;依赖于混凝土病害图像多特征的综合信息,灰度+颜色+纹理特征融合分类模型可将混凝土表面锈蚀和缺损的分类准确率提升至88%,多特征融合分类模型对于病害的分类判别稳定性显著优于单一特征分类模型。该研究可为混凝土表面病害图像分类提供有效方法,提升病害分类效率与准确性。     

快速图像分割和抠图技术研究

为解决现有算法速度慢、 集成度低的问题, 提出了改进的算法。利用图像分割算法Grabcut对图片的前景进行分割； 高效地生成三分图, 并以此作为基于三分图的抠图算法Shared Matting的输入； 综合处理抠图结果。针对该系统的特点, 使用下采样技术对Grabcut算法进行优化, 加快分割速度, 并对三分图生成算法和Shared Matting抠图算法进行并行性加速。仿真实验结果表明, 该系统适用性较强, 可用性较好, 并能在短时间内利用较少的交互量取得较理想的抠图效果。     

一种基于视觉的码率分配策略

提出了一种基于视觉的码率分配策略. 通过对人类视觉系统HVS的某些视觉特性进行分析,并对图像分段后获得的区域做出相应的视觉重要性估计,确定每个区域在主观意义上的视觉感兴趣值,将该值作为关键区域选择和码率调整的重要依据. 实验结果表明,利用该方法所获得的图像恢复质量符合人眼的主观判断,而且算法复杂度较低,具有较高实用价值.     

基于扩散的视觉显著目标检测

针对图像背景颜色和视觉显著检测目标信息颜色相近时,显著检测结果的精度和效率不高的问题,提出了一种基于扩散的视觉显著目标检测模型.首先通过对对称矩阵的构造并丢弃常数特征向量和辨别力进行了重新组合扩散矩阵,然后对扩散矩阵中的种子向量进行重新构造,最后将重新组合的扩散矩阵和重新构造的种子向量进行扩散,得出了基于扩散的视觉显著目标检测算法.实验结果表明:该算法较之前的算法有一定的改进,在背景颜色和视觉目标信息颜色相近的情况下,该算法显著目标检测效果有了明显的提升.     

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。