基于二维伽马函数的光照不均匀图像自适应校正算法

提出了一种基于二维伽马函数的光照不均匀图像自适应校正算法. 利用多尺度高斯函数提取出场景的光照分量,然后构造了一种二维伽马函数,并利用光照分量的分布特性调整二维伽马函数的参数,降低光照过强区域图像的亮度值,提高光照过暗区域图像的亮度值,最终实现对光照不均匀图像的自适应的校正处理. 通过与经典算法对比表明,本文算法可以更好地降低光照不均匀对图像的影响,提高图像的质量.      

径向基神经网络算法在车牌字符识别中的应用

提出一种基于径向基网络的汽车车牌字符识别算法.在预处理阶段,采用灰度化、自适应阈值分割去除图像噪声并增强图像对比度;在字符分割阶段,采用极限元素位置确定法实现独立字符分割;在字符识别阶段,利用自行构建的字符子块图像库对径向基神经网络进行训练.选取基于反向传播(BP)神经网络的字符识别算法和基于支持向量机(SVM)的字符识别算法与文中方法进行比较.实验结果表明:文中方法在识别准确率上具有明显优势,更适用于汽车车牌的字符识别.     

傣文贝叶经的图像增强与二值化方法研究

为了解决贝叶经图像背景不均匀及字符与背景颜色对比度较低给其二值化带来的困难,提出一种图像增强与Sauvola算法相结合的方法.首先使用同态滤波处理贝叶经图像背景不均匀的现象,然后使用灰度线性变换对其进行对比度增强,最后再使用Sauvola算法对贝叶经图像进行二值化.实验结果表明,同态滤波、灰度线性变换与Sauvola算法相结合的方法有效地解决了贝叶经图像背景不均匀和低对比度的问题,得到了清晰的二值化结果,适合于贝叶经图像的图像增强与二值化.     

基于结构特征的快递单手机号码识别算法研究

对基于结构特征的数字识别方法进行了改进,首先根据投影法准确定位出数字区域,接着对图像进行预处理、二值化、区域定位及字符分割等操作,最后根据数字结构特征对字符进行分类和识别.该方法不需要对图像进行倾斜校正、亮度调整、去噪等操作,节省了大量时间.实验结果表明,该算法准确率达到98%,耗时仅为5.52ms,满足实时性要求.     

一种钢坯表面喷印字符图像分割算法

为了提高钢坯表面喷印字符分割的效果,提出通过图像增强和滤波算法改善图像质量,解决钢坯表面喷印字符图像的分割问题.通过构造自适应阈值,自动分割图像进行字符串定位,并基于形态学处理、连通域分析设计了字符分割算法,解决了图像中存在的黏连和断裂问题.设计了一种掩膜保护字符的滤波算法,解决了细线噪声干扰问题,同时建立了相应的实验系统进行研究.结果表明:该算法效果较好,对字符图像黏连、断裂情况分割的正确率分别达到了99.6%, 98.3%,对细线噪声干扰类样本分割的正确率达到了97.9%.     

手写数字字符的边界特征提取

为提高图像质量,研究手写数字字符的边界特征提取技术.设计了一种图像预处理方案,给出了灰度化和二值化的具体算法公式,主要运用Roberts算子、维纳滤波和形态学处理三种算法成功提取出了手写数字字符的边界特征,字符边界清晰,内部饱满无空缺.该图像预处理方案为正确分割字符打下了良好的基础.     

梯度熵改进边缘检测的自适应阈值曲面分割算法

光照不均匀往往造成背景亮度不均和灰度分布范围较大,会导致图像分割困难和不准确.考虑图像的边缘信息受光线变化相对不敏感,引入梯度熵信息对Canny算法进行改进提取准确合适的边缘.采用最小二乘法的多项式曲面拟合获得阈值曲面,进而提出了基于梯度熵改进边缘检测的自适应阈值曲面分割算法.对多种背景灰度分布不均匀的图像进行算法验证...     

数字图像处理应用于车辆牌照识别的研究

探讨了将数字图像处理技术应用于机车车辆牌照识别的基本方法.在图像预处理部分,选用灰度差倒数加权平均算法对源图像进行滤波处理;应用分段线性变换算法增强图像对比度.通过边缘检测算法对车辆牌照进行准确地定位及对文字进行分割,完成对车牌上的字符的识别是利用各个字符的图像和字体的特征值,对其中每个字符进行有效、准确的识别.     

一种新的图像自适应水印算法

数字水印是数字媒体版权保护的一种有效方法.提出了一种新的基于DCT(Discrete Cosine Transform)域的盲图像自适应数字水印算法.该算法利用视觉系统HVS(Human Visual System)特性和图像的局部特点,自适应地选择量化步长对图像各个分块的直流分量通过量化来嵌入水印,同时为了弥补在感知容量小的分块直流分量上水印嵌入强度的不足,利用照度掩蔽特性对该分块的部分低频系数也自适应地嵌入同一水印信号,从而使水印的稳健性和不可见性之间达到很好的平衡.水印的提取不需要原始图像.实验结果表明该算法实现的水印具有良好的不可见性,并对常见的几种图像处理和噪声干扰也具有很好的稳健性,其性能优于其它文献上的相近算法.     

基于卷积神经网络的字轮式仪表双半字符识别

针对远程自动抄表系统中字轮式表盘出现双半字符导致识别困难的问题,提出一种基于卷积神经网络(CNN)的双半字符识别方法.对采集到的表盘图像,首先通过图像预处理和投影算法分割出完整字符和双半字符.鉴于实际图像中双半字符样本较少,不足以训练深度网络,该方法通过收集相邻数字的完整字符图像进行对齐拼接,再从中随机截取子图像从而建...     

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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