基于视觉显著性与边缘密集度的文本区域定位

为解决传统算法对文本区域检测查准率较低的问题, 从自然场景文本特性出发, 提出了一种基于视觉显 著性与边缘密集度的鲁棒性文本定位方法。 首先利用谱残差理论提取图像的显著性区域, 然后在提取的显著 性区域中寻找边缘密集度大的区域, 以此构建候选连通域, 利用少量的先验信息滤除其中的非文本区域。 在标 准数据集上的实验结果表明, 与单纯利用边缘特征进行文本区域检测的方法相比, 该方法可获得 70% 的综合 检测率。     

最大稳定极值区域与笔画宽度变换的自然场景文本提取方法

针对从背景复杂、视角多变、语言形式多样的场景图像中难以准确提取文本信息的问题,提出了一种基于最大稳定极值区域(MSER)和笔画宽度变换(SWT)场景文本提取方法。该方法结合MSER、SWT算法的优点,采用MSER算法的准确检测文字区域,建立文本候选区域,利用SWT算法计算文本候选区域笔画宽度得到候选文本区域的笔画宽度;根据笔画宽度图,利用连通域标记建立笔画宽度连通图,然后根据笔画宽度连通图,建立笔画连通图的启发性规则,删除非文本候选区域,并根据文本的几何特征分析及局部自适应窗口最大类间方差(Otsu)分割,有效提取出自然场景图像中的文本,文本提取的准确率、召回率及综合性能分别为0.74、0.64及0.68。仿真实验结果表明,在文本视角多变,字符大小、尺寸、字体各异的复杂条件下,所提方法具有较好的鲁棒性,适用于多语言和多字体混合的场景文本提取。     

自然场景图像中基于视觉显著性的文本区域检测

从自然场景图像中抽取文本信息有利于场景图像的内容分析.文中根据图像中文本通常在局部区域具有显著性的特点,提出多尺度包围盒视觉显著性模型,并利用该模型设计一种可以融合边缘和纹理信息的候选文本检测方法.首先在Lab颜色空间构造基于边缘和纹理信息的图像同质性,并利用它将图像映射到同质性空间;然后根据多尺度包围盒视觉显著性模型求Lab颜色空间的同质性均值图像;最后求同质映射图像与同质性均值图像的加权欧氏距离,将其作为显著性度量,以提取文本区域.自然场景图像的实验表明:与单纯利用边缘检测或同质性映射进行文本检测的方法相比,文中提出的方法能够更好地抑制背景的干扰,这有利于进一步将文本区域与背景剥离,进行更精确的文本定位.     

基于连通域阈值的自然场景文本图像分割技术

文章探讨了三类自然场景图像的基于纹理、边缘以及连通域文本定位方法的不同特点,并选取基于阈值的连通域方法,对复杂场景中的车牌图像中的文本实现图像的分割,最后分析了此方法在自然场景文本定位方法今后的应用前景。     

基于连通区域的标志牌文本提取方法

在对各种文本定位与提取方法分析比较的基础上,针对标志牌文本的具体特点,提出了一种基于连通区域的标志牌文本提取方法———在灰度图像中定位标志牌区域,二值图像中提取标志牌文本,并用VC 编程实现对采集的自然场景下的标志牌文本图像进行了实验,结果证明,该方法能够准确定位并提取自然场景下的标志牌文本,获得文本字符。     

基于色彩聚类的自然场景文本检测

基于场景图像背景复杂,图像中的文本变化多样,提出一种基于色彩聚类的自然场景文本检测算法。其步骤为:首先,用K-均值聚类算法将彩色图像聚成5种色彩层,分析各色彩层中连通域外接矩形的几何特性,去掉离散的非文本连通域;然后,根据相邻连通域外接矩形的几何性质和空间位置关系,将离散的连通域连接形成候选文本块;最后,通过分析候选文本块的几何特性和边缘密度验证文本,得到最终文本检测结果。实验结果证明了本文算法的有效性和可行性。     

一种基于连通域的蒙古文文档图像版面分析方法

版面分析是一个将文本页面图像分割成不同区域,并标定区域类型(如文字、图片、表格等)的过程,与字符识别具有同等重要的地位.提出了一种基于连通域的蒙古文版面分析方法,它提取文档图像中所有连通域,根据连通域的大小进行聚类,从而可以得到文字连通域和非文字连通域,达到分割版面的目的.实验证明,该算法能够对蒙古文书籍版面进行准确的分析.     

图像垃圾邮件中文本区域的自动提取方法

图像中的文本区域为判别图像垃圾邮件提供了重要依据.为了获得图像中的文本区域信息,提出了基于Hough变换提取图像中倾斜文本区域的算法和降低图像背景干扰的八邻域细小边缘去除算法,实现了一种不受图像中文本颜色、字体、大小、位置、方向限制的文本区域的自动提取方法.在包含100幅垃圾图像的数据集上进行提取图像文本区域的实验.实验结果显示,新方法具有良好的文本区域提取性能.     

基于局部显著文字型区域的场景文本提取算法

利用局部显著文字型区域描述结合连通分量分析思路,文章提出一种复杂背景下针对场景文本稳健的文本提取算法.该算法首先通过灰度的局部显著变化和显著多方向边缘强度定位图像的显著文本区域;然后依据区域灰度变化将原始图像进行分割,获得显著区域的连通分量包括文本分量和非文本分量;接着用一个级联分类器基于字符属性滤除部分非文本连通分量,最后统计文字包围盒的边缘方向分布信息,对每个候选连通分量提取8维的特征送入SVM分类器进行验证,最终定位出文本区域.实验结果表明,这种基于显著区域提取文本的算法有效地结合了文本的区域特性和文本连通体的笔画属性,在保证文本提取正确率的同时提高了算法速度,测试结果表现出较满意的性能.     

非文本区域优先的版面分析方法

版面分析目前已成为提高汉字识别系统效率的关键技术之一。针对中文版面较为复杂的特点,本文提出一种非文本区域优先的版面分析方法。该方法提取文档图像中所有连通域,根据连通域的大小进行聚类,从而可以得到文字连通域和非文字连通域,以达到分割版面的目的。实验结果表明,这种方法能够对比较规范的中文版面进行分析,具有较高的效率和较好的适应性。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.