一种基于多尺度结构自相似性的图像超分辨率重建算法

多尺度结构自相似性是指图像中存在大量相同尺度,以及不同尺度相似结构的性质。提出一种基于多尺度结构自相似性的超分辨率重建算法;该方法通过图像旋转和金字塔分解,将输入图像的先验信息附加到训练库中;并对样本图像块聚类,分别训练针对各类的多个字典。在图像重建阶段,自适应选择最优字典;并利用相似图像块间的关系建立非局部约束项重建图像。最后利用迭代反投影算法进行图像后处理,进一步提升图像的超分辨率重建效果。实验结果表明,与SCSR、SISR和ASDS算法相比,算法能够取得边缘更为清晰的超分辨率重建效果。     

一种基于多尺度结构自相似性的图像超分辨重建算法

多尺度结构自相似性是指图像中存在大量相同尺度以及不同尺度相似结构的性质。本文提出一种基于多尺度结构自相似性的超分辨率重建算法,该方法通过图像旋转和金字塔分解将输入图像的先验信息附加到训练库中,并对样本图像块聚类,分别训练针对各类的多个字典。在图像重建阶段,自适应选择最优字典,并利用相似图像块间的关系建立非局部约束项重建图像。最后利用迭代反投影算法进行图像后处理,进一步提升图像的超分辨率重建效果。实验结果表明,与SCSR、SISR和ASDS算法相比,本文算法能够取得边缘更为清晰的超分辨率重建效果。     

利用位置字典对的人脸图像超分辨率方法

针对基于稀疏表示的人脸超分辨率算法存在的字典尺寸大、训练时间长等问题,提出一种基于位置字典对的超分辨率重建方法.由于同一位置的人脸图像块具有相似的结构和内容,更有可能用相同的字典原子进行线性组合表示,因此把训练人脸图像按位置分块,首先为每个位置训练一个位置字典对,利用获得的多个位置字典对,对低分辨率测试人脸图像进行基本重建,然后应用残差补偿方法对位置块进行补偿.实验结果表明,由所提方法重建的人脸图像具有更好的视觉效果,与应用原始图像块进行稀疏表示的图像超分辨率算法相比,平均图像结构相似度指标值提高了0.082,同时字典训练时间缩短了约5倍.     

基于自适应加权压缩感知的图像超分辨率重建

压缩感知理论被广泛应用于从少量随机观测中精确地重构原始信号,基于压缩感知理论来实现图像的超分辨率重建,在利用图像的局部稀疏性先验的基础上,采取了以下两项措施：一是通过对图像降质模型的估计,采用K-奇异值分解(K-singular value decomposition, K-SVD)算法构建过完备字典对,依据同一图像高低分辨率观测在对应字典下稀疏表示系数相似的特点,将字典对所表示的高低分辨率图像间的映射关系带入目标函数中,避免了降采样和模糊算子难以抽象为矩阵形式对求解造成的影响;二是在待超分辨率图像稀疏编码时提出一种自适应加权的梯度投影稀疏重构(adaptive weighting gradient projection for sparse reconstruction, AWGPSR)算法,克服了传统正交匹配追踪(orthogonal matching pursuit, OMP)算法在这一步需要固定稀疏度的缺陷,可获得更加精确的稀疏表示系数。结合得到的稀疏表示系数与高分辨率字典可以重建出图像的高频分量,将重建的高频分量与低频部分融合可以得到最终的图像超分辨率重建结果。实验结果表明,...     

联合深度置信网络与邻域回归的超分辨率算法

为了提高重建的质量和速度,提出一种联合深度置信网络与邻域回归的超分辨率算法.一方面,结合字典学习与神经网络表示的联系对传统的深度置信网络进行调整,采用该网络模型实现字典学习,充分利用该模型突出的学习能力,使字典具有更好的特征表达能力,从而提高图像的重建质量.另一方面,在基于字典学习的超分辨率框架中融入邻域回归思想.首先,利用最近邻域算法确定字典原子的最近邻域映射关系;然后以此为基础,结合邻域回归方法,离线计算高、低分辨率投影矩阵;最后在重建过程中将该投影矩阵应用于图像重建.该方法避免了字典学习中的系数求解过程,降低了计算的复杂度,提高了重建的速度.实验表明,算法具有更高的峰值信噪比和结构相似度,同时极大地提高了图像的重建速度.     

基于半耦合字典的快速图像超分辨率重建算法

为了提高图像超分辨率重建的效率与质量,考虑到高、低分辨率稀疏表示系数的不同,改进了锚定邻域回归算法,并结合半耦合字典学习算法提出了一种快速图像超分辨率重建算法.首先采用半耦合字典学习算法得到高分辨率字典、低分辨率字典及映射矩阵;再采用岭回归算法求解低分辨率稀疏表示系数,并根据高分辨率稀疏表示系数与低分辨率稀疏表示系数之间的映射关系,得到高分辨率稀疏表示系数;然后,根据输入图像块特征寻找字典中与其最相关的字典原子,计算该字典原子所对应的投影矩阵,进行超分辨率重建.仿真结果表明:提出的算法不仅在重建速度上表现更快,重建图像的质量也得到提高,在客观指标和主观效果上均取得更好的效果.     

基于非局部自适应字典的SAR图像迭代去噪算法

为了更好地利用SAR图像携带的信息,相干斑噪声的抑制成为各国学者研究的热点之一.结合稀疏表示理论和图像的非局部自相似理论,提出了一种基于非局部块匹配与自适应字典的K-singular value decomposition(K-SVD)的synthetic aperture radar(SAR)图像迭代去噪算法.首先,在每次迭代中,利用非局部块匹配算法对上一次迭代的结果进行匹配分组,然后对每组相似块进行自适应字典更新,并用图像块替换字典原子来提高字典训练的效率,最后通过K-SVD的迭代实现SAR图像的去噪效果.实验结果表明,该算法具有更好的去噪能力,能更好地保持图像的细节和纹理等有用信息.     

支持向量机多特征分类学习的超分辨率复原

支持向量机(SVM)单一特征分类学习的超分辨率复原算法通过离线建立分类模型和减少样本库规模,降低了传统基于范例学习算法的样本块误匹配情况,增强了图像质量和计算速度.但由于图像特征的多样性,此类算法易造成复原结果的不稳定.本文给出一种以支持向量机多特征分类学习为基础的复原算法,将图像对应的颜色和纹理分类信息存储在样本库中,经过预分类筛选出样本子集,在高频预测时段直接从多特征相似的样本子集里实施准确的匹配检索.实验结果表明,相比于传统算法,本文算法的PSNR和SSIM值均有了一定提升,进一步精确匹配了低分辨率图像样本库,提高了复原效果.     

基于多尺度图像块分类的字典学习算法

针对传统字典学习算法未考虑训练数据集流形结构的问题,提出一种基于KD树分类的多尺度字典学习算法。首先在预处理阶段建立图像高斯金字塔,提取不同尺度下各层图像的角点并建立KD树进行分类,以各类角点为中心截取图像块并生成每层图像的训练数据集来完成各个子字典的学习。在字典训练阶段,提出一种基于局部保持投影的多原子更新算法,在保持字典中各类原子集的流形结构的情况下进行原子更新,高效训练出自适应稀疏字典。对测试图像进行压缩感知重构实验,仿真结果表明,该算法在保证图像重建精度的前提下,显著提高字典学习效率。     

基于二维稀疏表示的人脸超分辨率重构算法

在分析人脸超分辨率算法和二维稀疏表示的基础上,提出基于二维稀疏表示的人脸超分辨率重构算法。与一维稀疏表示中将图像块转换为列向量不同,本文考虑到二维图像列与列之间的近邻关系,对图像块进行二维稀疏表示;在字典训练中,对每组图像块的每一列训练高、低分辨率字典,提出二维K-SVD算法对字典进行训练,减少字典训练消耗的时间,同时能够改善超分辨率人脸的质量。采用中科院CAS-PEAL共享人脸图像数据库进行仿真实验,实验结果从主、客观质量均验证了本文算法的有效性及先进性。     

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.     

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.     

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