基于边缘梯度的散焦图像深度恢复

在散焦图像中,点的模糊程度随物体的深度而变化,因此可以利用散焦图像中点的散焦程度来估计物体的深度信息。本文提出了一种基于散焦图像中物体的边缘梯度关系来恢复图像深度图的新算法,用一个已知参数的高斯函数对图像进行再模糊,然后求出模糊后的物体边缘梯度,再与原图像中物体边缘梯度相比,再将该比值与图像的深度关联,求出图像中物体边缘处的深度,再利用后续深度插值方法和深度图优化恢复出整幅图的深度信息。这种算法仅需要一幅图像即可进行深度信息恢复,有较好的有效性。     

基于圆分割的鱼眼镜头图像畸变校正算法

针对应用鱼眼镜头拍摄的图像产生了严重的畸变的问题,提出了一种基于圆分割的校正算法.该算法充分利用了鱼眼图像圆形结构这一特点,将其分割成同心圆,再利用函数法对畸变图像进行校正.微调系数的引入,使得算法更灵活,这样能根据鱼眼镜头与实际物体的距离来调整微调系数的大小,得到更理想的校正图像.Matlab实验结果表明:应用本算法能得到比较满意的校正结果,并且该算法所花费的计算时间少,使其能适用于实时监控系统.     

基于风险决策的混合高斯背景建模

对于固定摄像机的人体运动目标的检测,在现有混合高斯模型中,往往希望混合高斯模型中高斯函数的个数数目越大越好,同时现有算法对场景内每个像素点都采用统一的背景模型参数更新规则,每获得新的视频帧图像,都要对图像内所有像素点的所有高斯函数参数进行更新,这会带来庞大计算量,影响算法实时性。本文针对高斯背景建模算法的这种特点,对有新物体移入或物体移出当前场景时的情况,提出了改进的高斯建模算法,引入风险决策应用于前景目标的突变判断中,并通过实验验证了改进的算法在目标检测率和系统实时性方面的改进。     

一种新的基于高斯偏移差分过滤器与方向图的图像分割算法

为了使图像分割算法通用性更强,利用高斯偏移差分过滤器模拟人类视觉机制模型寻找图像中有纹理区域,使用方向图算法界定目标边缘,最终得到图像分割结果.该算法能有效地克服图像背景上的噪声以及前景目标轮廓不明显的缺陷,成功分割提取出图像的前景目标.试验证明,该算法鲁棒性强,具有一定通用性且无需先验知识.     

一种改进的路面裂缝图像分割方法

针对公路裂缝检测中的图像分割问题,运用机器学习领域的方法,以裂缝图像为研究对象,在深入分析经典K-Means聚类算法以及高斯混合模型（Gaussian Mixture Model, GMM）之后,提出一个利用全局K-Means和高斯混合模型来对公路裂缝图像进行分割的方法。该方法在全局K-Means聚类算法的基础上,采用改进策略,同时,将传统GMM的每一个概率分布,进一步再细分成单个的概率成分,在辅助变量计算过程中,采用EM算法。仿真图像和实际裂缝图像实验结果显示,本研究得到了比使用传统K-Means算法和普通GMM的分割方法精度更高、稳定性更好的分割结果。     

一种基于纹理特征的图像检索方法的实现

对图像纹理特征进行了研究,采用改进的共生矩阵算法来提取纹理特征.在此基础上,通过高斯归一化法用纹理特征作为图像检索特征,给出了利用该特征的图像检索算法.从实验结果可以看出,对于具有明显的纹理特征的图像数据库利用改进的共生矩阵提取算法具有较好的检索性能,可以得到较好的检索效果.     

基于独立成分分析的自适应图像滤波算法

近年来提出的独立成分分析（ICA）算法基于非高斯分布度量,可以有效提取图像边缘等重要信息。基于FastICA算法,利用＂MIT图像数据库＂分别对不同场景图像集进行图像块采样,构建基于单一场景的训练集,训练各训练集得到ICA滤波器,得到并分析各组ICA滤波器对同类型图像集的滤波结果。实验表明ICA滤波可以实现不同场景图像的稀疏编码,且滤波结果具有对训练集自适应拟合能力。     

一种提取体式显微镜图像特征点的方法

精确提取标定板的特征点是体视显微镜标定的关键,其结果会影响体标定的准确性和稳定性。针对体视显微镜图像噪声大和部分图像清晰度低的问题,提出一种基于分水岭算法的标定板图像特征提取方法,利用区域信息来表征图像特征,以提高检测的稳定性。首先采用高斯高通滤波器锐化得到边缘清晰图像;然后用大津法对图像二值化,并进行形态学腐蚀,接着采用分水岭算法提取图像特征区域,最后通过求取区域几何重心来获取特征点。实验结果表明该特征提取方法具有较强的稳定性。     

基于狄利克雷分布和参数分析的高斯混合模型图像分割算法

传统的高斯混合模型对于含有噪声的图像不能进行有效的分割。针对有噪声图像的分割问题,提出了一种基于狄利克雷分布和参数分析的高斯混合模型图像分割算法。首先采用高斯函数对像素计算先验概率值,然后采用狄利克雷分布和定律关联像素间的邻域信息,并利用梯度下降法优化参数。实验结果表明,本文算法对无噪声和有噪声图像的分割结果比传统方法更有效,误分率更低。     

基于颜色和空间特征的图像检索

提出一种新的基于颜色和空间特征的图像检索算法。首先,将检索图像转换为HSV颜色空间并进行量化,提取环形颜色空间信息熵作为颜色空间分布特征。其次,计算每个像素点的多邻域的量化颜色值的一、二阶中心矩,利用各阶统计矩的信息熵来表征图像颜色的局部空间特征。最后,对特征向量进行高斯归一化,采用特征向量的L1-norm距离计算彩色图像的相似度并进行图像检索。试验结果表明该方法比CDE和Geostat算法具有较好的检索效果。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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