SURF算法在局域盲人图像导航中的应用

局域盲人图像导航即在建立基准图像信息特征库的基础上,对实时拍摄图像提取特征并与基准图像特征库进行匹配,得到相应地理信息并语音输出给盲人,从而实现导航的一种方法。本文基于SURF算法对图像特征进行匹配,首先提取SURF特征点,然后采用Hessian矩阵迹快速索引匹配以及匹配点距离差平方和的相似性度量方法进行匹配。实验表明SURF匹配算法优于SIFT匹配算法,并可实现快速、鲁棒、准确匹配,为实现盲人局域图像导航奠定理论基础。     

复杂环境下尺度不变特征的检测与匹配技术研究

针对农业机器人复杂的工作环境,引入了一种新的鲁棒特征点检测算法——SURF算法,其对光照变化、旋转、尺度变化等具有很好的鲁棒性,精度能达到亚像素级别;在此基础上,利用最近邻法则结合BBF（best bin first）搜索算法,对SURF特征点进行精确匹配,实验表明,本文所提出的方法鲁棒性或实时性较目前常用的Harris算法和SIFT算法更好,可应用在机器人视觉定位、地图构建、智能导航等方面,具有一定的理论和应用价值。     

机器人视觉导航的几种特征点方法比较

针对移动机器人视觉导航中移动速度较快且计算能力较弱、视觉路标的图像特征检测与匹配时间之间存在矛盾这一问题,提出了选择合适的满足实时性的特征检测方法.对机器人视觉导航中获得图像特征常用的特征点法(如KLT,SURF,SIFT,Harris等)进行了探讨.通过对移动机器人导航中的图片采用不同方法进行测试,比较了不同方法所需...     

SURF算法及其对运动目标的检测跟踪效果

视频图像的特征点提取和描述是智能交通系统中运动目标跟踪的一项关键技术。由于场景的复杂性、环境的变化以及目标运动的影响,Harris角点检测算法和尺度不变特征变换(SIFT)算法的精度和稳定性都不够,而加速鲁棒特性(SURF)算法具有很强的鲁棒性,运算速度比Harris角点检测算法和SIFT算法有明显提高。应用SURF算法对视频图像进行特征点提取和匹配,并结合聚类分析和卡尔曼滤波对匹配的目标进行跟踪。实验表明,SURF算法对亮度变化具有很强的鲁棒性,并且速度比较快。     

基于SIFT的新特征提取匹配算法

针对传统的图像匹配算法特征点不稳定和匹配时间慢的问题,提出了一种改进的尺度不变特征变换(SIFT)图像匹配算法。首先对传统的Harris角点构造高斯多尺度空间,使角点具备多尺度不变性;然后采用Canny边缘提取算法修饰Harris角点以增加稳定特征点数量;最后构造SIFT特征描述符,计算多幅图像中对应特征点描述子的欧式距离,完成特征点对的匹配。实验结果表明:相比于传统的SIFT算法和SURF算法,研究所提出的方法能够有效地提高特征点匹配精度,减少图像匹配时间。     

基于FAST角点检测的局部鲁棒特征

针对目前流行的SIFT、SURF等局部特征存在运算复杂、匹配及后续处理实时性差等问题,在FAST角点检测的基础上,提出了一种新的视觉跟踪特征算法. 该算法能克服实际应用中噪声及室外光照变化的影响,并能快速匹配特征点实现实时处理. 实验结果表明,该视觉跟踪特征算法具备运算量小、实时性高的特点,并且能保证匹配精度及鲁棒性优于原有的视觉跟踪特征.      

SURF与RANSAC组合图像拼接算法

针对目前基于尺度不变特征变换匹配算法(scale invariant feature transform,SIFT)的图像拼接算法存在的算法复杂度高、算法的特征点匹配精度不准的问题,提出了一种SURF和RANSAC组合的拼接算法。算法从特征点提取匹配出发,基于筛选过滤的提纯思想对初步筛选的特征点进行优化从而达到提高融合质量的目的。筛选过程使得算法具有一定的鲁棒性,同时算法降低了时间上面的消耗。基于SURF和RANSAC的组合图像拼接算法可实现高质量的图像拼接,是一种加速图像拼接速度兼具鲁棒性的图像拼接算法。     

基于改进SURF的图像配准关键算法研究

针对图像特征匹配算法维数高,实时性低的缺陷,研究了SURF特征匹配算法,并对其进行了改进。首先在图像的尺度空间中提取SURF特征点,并生成扩展的特征描述向量。然后建立KD-Tree特征结构,采用BBF查询机制进行最近邻查询实现特征点快速匹配。实验结果表明,SURF算法进行特征检测的时间是SIFT算法的1/3;使用BBF进行特征匹配,匹配速度提高了2—3倍。     

基于改进SIFT算法的无人机影像匹配

针对SIFT算法特征描述符计算复杂、时间效率较低的问题,提出了一种改进的SIFT算法,并将其应用于无人机倾斜影像匹配.算法首先利用SIFT算法进行特征点检测,基于BRISK描述符对提取的特征点进行描述生成其特征描述符,并基于Hamming距离作为特征匹配的相似性测度,在此基础上,利用比值提纯法(NNDR)进行粗匹配,最后采用RANSAC算法并结合均方根误差(RMSE)进行约束,对粗匹配结果进行筛选,剔除错误匹配点对,得到精确匹配结果.为了验证该算法的有效性,利用4组无人机影像数据进行实验并与SIFT算法和SURF算法进行比较,结果表明:算法在保证较高准确率的同时能够得到亚像素级的精度,且能够有效地提升时间效率,具有较好的稳定性.     

基于Android和SURF算法的图像识别系统的研究

图像识别技术是计算机视觉和图像处理领域里的重要研究课题之一,在军事及民用领域应用广泛。在目标检测算法中,基于特征的方法具有压缩信息量、执行速度快、精度高等优点,SIFT算法便是其中之一,但传统的SIFT算法应用于图像识别过程中数据量大、计算耗时长,提出了一种基于SURF算法的图像识别方法,并使用Android NDK调用OpenCV在Android手机平台上实现了一套图像识别系统,结果表明,基于SURF算法的图像识别系统识别效果和实时性更好、具有更强的鲁棒性。     

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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