非对称广义高斯亮度迁移与局部信息融合的土壤图像增强

【目的】为减小土壤图像成像环境条件差异对机器视觉识别土种精度的影响,提出对野外自然环境下采集的土壤图像可控光照增强。【方法】首先,用非对称广义高斯曲线拟合土壤图像V分量直方图,并在拟合曲线中引入目标迁移量,完成图像亮度迁移,实现土壤图像全局亮度可控增强;然后,利用全局和局部信息估计图像在局部区域上的光照权重,引入目标亮度,根据权重确定局部增量,并将局部增量叠加到原始V分量,实现基于局部增量的土壤图像亮度增强;再利用sigmoid曲线,将非对称广义高斯曲线亮度迁移获得全局亮度增强结果与基于局部增量的亮度增强结果融合,获得土壤图像的亮度可控增强。最后,根据色比不变性原理,分别对原始土壤图像R、G、B分量进行颜色校正。【结果】仿真实验表明:土壤图像从低亮度向高亮度迁移时,增强图像与目标图像在V分量上各对应像素的亮度差异均值为10.5267,与目标图像亮度均值差异为0.2451;从高亮度向低亮度迁移时,各对应像素的亮度差异均值为10.7430,与目标图像亮度均值差异为0.2721;本文所提算法在亮度控制上较其他算法具有更高的精度;主观质量评价表明,以原图亮度为基准,[-30,30]为土壤图像有...     

基于半监督离散度的土壤彩色图像阴影检测

[目的]由于光照及土壤心土自然断口凹凸的影响,机器视觉采集终端获取的土壤图像中存在阴影,为避免对后续土种识别造成干扰,研究对土壤图像进行阴影检测的方法.[方法]通过对土壤彩色图像HSI颜色空间阴影与非阴影分析,发现阴影与非阴影分别在色调(H)和亮度(I)分量具有一定的分离特性;首先,为了增大分离特性用于土壤图像阴影检测...     

小波域彩色图像的混合噪声抑制算法

图像噪声抑制是数字图像复原预处理中的重要环节。针对传统方法处理混合噪声出现的色调变化问题,同时为进一步提高图像去噪效果,本文提出一种改进的维纳滤波算法。在HSI色彩空间中对输入彩色图像的亮度分量进行小波分解,然后选取以图像低频分量当前像素为中心的不同模板邻域方差最小的模板,计算出模板内像素值相对于中心位置基于欧氏距离加权的均值作为输出图像相应位置的模板中心像素值。实验结果表明,该算法不仅能够使处理后的彩色图像保持原始图像的色调,还进一步提高了对图像中噪声的抑制效果。     

接触网风偏检测的亮度矩寻优分割算法

介绍电气化铁道接触网风偏视觉检测原理,以视觉检测的图像处理为背景提出一种能够适应不同光照条件的彩色图像分割算法.该算法融合彩色图像的一阶亮度矩和对比度信息,通过线性亮度寻优优化图像的一阶亮度矩,并以图像的初始一阶亮度矩为基准亮度进行对比度拉伸,实现对目标区域颜色特征的放大;同时,以特征点靶面的像素面积为目标值,以不同寻优亮度下图像的合格像素点统计量为寻优变量,对两者的关系曲线和最佳目标逼近方式进行了深入研究,确定合理的初始寻优亮度及寻优方向.最后,以现场采集图像为训练样本对算法进行验证和分析.研究结果表明:该方法能够实现彩色空间下接触网风偏目标特征点的有效、准确分割,对复杂光照条件具有良好的适应性和算法鲁棒性.     

一种基于视觉适应性的图像增强算法

模拟真实场景反应在人眼中形成图像的过程,考虑到邻域间干扰、光照不均匀、媒介传递率下降引起的图像退化,提出了一种新的图像增强算法。依据对视觉现象中对比灵敏度、亮度适应能力和侧抑制现象的研究,建立了一种图像退化模型的视觉适应性模型,该模型求解方案包含3个过程:用于消除邻近像素相互影响,给人眼提供更多细节的去卷积过程;据锥细胞亮度适应能力提出的,为其工作提供最佳工作光照条件的亮度调整过程;模拟侧抑制机理提出的对比度拉伸过程。对比现有图像增强算法的增强结果,实验结果表明该方法的视觉适应性解,在增强图像细节、提升对比度、增强结果的视觉愉悦性方面取得了较大进步。     

一种基于全局和局部光照估计的Retinex图像增强算法

具有色彩还原特性的Retinex算法,可以实现图像对比度、亮度提高及色彩还原;但是增强后的图像色彩饱和度下降严重,色彩失真,其关键在于光照分量的估计失真。针对上述问题,提出了基于全局光照和局部光照细分的Retinex增强算法,实现了图像光照分量的精确计算;并通过实验证明增强后的图像在提高亮度突出细节的同时,最大程度保持了原来的真实色彩。     

可见光与红外图像彩色融合中的热目标增强方法

研究树林、陆地场景下可见光与红外图像彩色融合中的热目标增强方法.利用拮抗视觉特性在YUV空间融合可见光与红外图像,增强二者的独有特征;在色彩传递阶段,使用3×3大小的十字形窗口定位红外图像的热目标,当窗口的局部均值大于红外图像的整体均值时,确定该像素点处于热目标区,表征红色与亮度(Y)差异的V分量值根据局部均值与整体均值之比进行增强.仿真结果表明,算法用浓烈的红色突出红外图像的热目标,有效地提醒观察者注意感兴趣的目标,同时,可见光图像的场景细节被赋予与白天光照下彩色图像类似的自然色彩,改善了场景的深度感知,提高了形势意识能力.     

基于小波和分块同态滤波的变光照图像增强方法

为提高变光照情境下图像质量,针对部分图像存在亮度不均、对比度低的问题,提出了基于小波与分块同态滤波的图像特征增强算法.首先将图像从原始色彩空间转换为H SV空间,以图像亮度分量V作为增强对象;然后利用小波变换代替分块同态滤波中的传统傅里叶变换对亮度分量分解,并对小波分解的子图像进行分块后进行高通滤波处理,对滤波后的图像...     

空间加权模糊C均值聚类图像分割算法

为了提高模糊C均值聚类(FCM)算法用于图像分割时对噪声的鲁棒性,在FCM算法中引入了图像像素的邻域约束,提出一种空间加权模糊C均值聚类图像分割算法。首先根据邻域像素的模糊隶属度函数值,定义像素分类标记的局部先验概率,然后将该局部先验概率融入标准的FCM算法的目标函数中,从而提出一种空间加权模糊C均值聚类图像分割算法。仿真实验通过合成图像和真实图像验证了该算法的有效性和鲁棒性。     

吸引权重加权FCM的土壤图像阴影检测

【目的】自然环境下机器视觉采集的土壤图像存在阴影，而阴影检测是后续亮度归一化和土种识别的重要预处理工作，基于此提出算法对机器采集的土壤图像进行阴影检测。【方法】首先，对图像的L分量和I分量的密度峰值集进行优化截断对齐，通过高斯平滑获取主峰值点，得到基于L分量和I分量的2因素密度峰值，作为改进模糊C均值（FCM）的自适应初始聚类中心；然后，引入拉伸因子对数据进行拉伸，提升数据差异；最后，定义基于全局密度和类面积的吸引权重，重构FCM优化模型，实现基于FCM的土壤图像自适应阴影检测。【结果】提出的算法检测的阴影区域和非阴影区域的平均亮度标准差分别为25.988 0，27.981 4，比对比算法降低了1.04%~32.23%；提出的算法平均迭代次数和平均运行时间分别为3次和1.515 8 s。【结论】提出的算法可实现自然环境下土壤图像阴影检测，具有检测精度高、时间花销小的特点。研究结果为土壤图像阴影检测提供了参考。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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