三目立体视觉外极线校正及其FPGA实现方法

提出一种三目立体视觉外极线校正的快速算法.3个摄像机呈直角三角形配置,且已知摄像机透视投影矩阵.根据校正基本约束确定校正后的图像平面,利用图像不变形约束计算校正所需的三阶矩阵,用于在平面仿射坐标系下对图像进行重取样,使图像的行列对齐.给出了基于FPGA的实时计算三目立体视觉外极线校正的硬件实现方法.在时钟频率为60 MHz,图像可分辨的像素数为640×480时,三目立体视觉外极线校正速度达到48帧/s.     

一种立体视觉图像的特征选择与匹配方法

从立体图像对中获取精确的三维信息需要进行相机建模、标定和图像点的匹配。提出了特征点的选取，利用金字塔图像结构进行立体匹配，以及对匹配点进行整体性检验的准则。实验表明，该算法匹配速度快，错误概率小，匹配点在整个景物中分布均匀。     

多视成像实时校正与立体显示

手工摆放的平行摄像机阵列所拍摄的多视点立体图像往往会产生垂直视差. 为了消除多视点图像的垂直视差, 必须进行多视点图像的校正. 提出一种简单有效的多视图校正算法, 并基于该算法构建了自由立体显示系统. 应用多线程进行摄像机软同步以及后续的实时优化. 当摄像机图像的上传分辨率为1 280×960、上传速率为25 帧/s、目标3D 显示器的分辨率为1 920×1 080 时, 采用双线性插值, 可达到20 帧/s 左右的显示速率; 若采用复杂度更低的插值方法, 则可达到20 帧/s以上的显示速率. 该算法实现了8路摄像机实时校正和立体显示的3D电视系统.     

一种立体视觉图像的特征选择与匹配方法

从立体图像对中获取精确的三维信息需要进行相机建模、标定和图像点的匹配［１，２］．提出了特征点的选取；利用金字塔图像结构进行立体匹配，以及对匹配点进行整体性检验的准则。实验表明，该算法匹配速度快，错误概率小，匹配点在整个景物中分布均匀。     

基于光度立体视觉的起皱织物表面形态重建研究

提出一种基于光度立体视觉方法对织物表面进行三维重建，先利用合成图像验证该算法，再将其应用于真实织物，该算法中结合了有限差分法，来获取织物的三维轮廓数据，并采用四个特征参数定量描述织物的起皱程度。     

一种基于三阶亮度校正的平面视频转立体视频快速算法

本文提出了一种新的平面视频转立体视频的快速算法.这种算法能够实时的将平面视频转换成立体视频,并能在三维显示设备上呈现出逼真的立体效果.首先将原始平面视频中的图像按照高斯分布进行立体变换,然后将视频中的图像序列生成加权平均亮度图,并将亮度分为3个等级,分别对这3个等级区域中的图像进行立体校正,最终得到完整的立体视频.我们的方法替代了传统方法中,生成深度图像的步骤,从而大大的提升了运算的速度,能够在原始平面视频的实时播放过程中,直接输出带有立体效果的画面.     

基于立体图对的颜色校正算法设计

基于多摄像机的视觉应用中通常假设统一的颜色响应。但是当摄像机之间存在较大的成像特性差异或光照变化时,所获得的立体图对间就会出现严重的色彩差别。这种差别会导致后续颜色匹配的不准确,并进一步影响立体视觉算法的性能。为了解决这个问题,提出了一个鲁棒的基于图像分割和特征点匹配的颜色校正算法。和传统的全局校正或者有参考物体的校正算法不同,提出了一种基于区域的校正算法。该方法不仅避免了全局校正算法无法满足局部需求的矛盾,同时也摆脱了设置参考物体的复杂和低效。大量实验证明了所提出算法的有效性和鲁棒性。     

基于立体校正的快速相位立体匹配

立体匹配技术一直是立体视觉领域研究的重点与难点。针对立体匹配的效率与精度问题,提出了一种基于立体校正与四步相位移相结合的方法来提高立体匹配的速度与精度。首先,通过Bouguet立体校正算法将左右相机拍摄的图像进行立体校正,使匹配点在左右相机上成的像位于同一水平线上。然后,采用四步相移法获取精确的各像素绝对相位值,并通过双向线性插值法获得了稠密匹配点,并提高了立体匹配的精度。最后,通过对标准台阶零件进行测量与精度分析,实验结果表明该方法能够快速、准确的实现稠密的立体匹配,满足工业应用的需求。     

一种灵活的立体图像校正方法

针对现有立体图像校正算法在校正图像时容易引起分辨率及图像内容损失的问题,提出了一种新的立体图像校正算法.首先突破了传统基于标定的校正算法必须使摄像机水平轴平行于光心连线方向的限制,提出了一种能够灵活选取坐标轴方向的方法.然后将光心位置差异引起的垂直视差分解为两个与光心位置相关的分量,并利用最小二乘法估计出一个相似变换和一个仿射变换,完成对摄像机光心的校正.实验结果表明,所提出的算法生成的左右立体图像的分辨率及内容损失大约近似仅有欧几里得方法的1/2,且对垂直视差的消除要优于欧几里得方法.     

基于奇异值分解的无参考立体图像质量评价

针对非对称失真立体图像,提出了一种基于奇异值分解的无参考评价算法.该方法首先考虑人眼对空间频率变化敏感的特性和双目融合特性,对立体图像进行Gabor滤波,基于奇异值分解的融合策略生成融合图.然后,采用亮度加权直方图的局部二值模式算法分别对融合图、左右子图像提取特征,并将左右子图像的特征向量融合、采用欧几里得距离和夹角余弦进行向量之间的比较;为度量非对称失真差异,利用图像相似度算法计算左右子图像之间的相似性.最后,将融合图的特征向量、子图像的融合及比较特征向量、子图像的相似度特征向量级联,利用支持向量回归(SVR)算法完成特征到主观质量分数的回归映射.在LIVE3DⅡ、Waterloo-IVCⅠ和Waterloo-IVCⅡ立体图像库上对本算法进行测试.实验结果表明,本算法性能良好,优于目前主流的立体图像质量评价算法.     

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