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1.
首先对图像进行Gabor小波分解,为了解决图像的提取特征有更好的的空间局部性和方向选择性,选用Gabor作为人脸特征的提取方法。并采用RBF神经网络利用其逼近能力强,收敛速度快、较强的适应性以及很强的非线性映射等功能,作为分类器对所提取的人脸有效特征进行识别。  相似文献   

2.
针对NMF在识别人脸图像特征时分解速度慢,基空间不适应欧氏距离度量的缺点,提出了一种基于小波变换和非负矩阵基矩阵正交化的人脸识别方法.利用小波变换对人脸图像进行变换,选择LL分量既能抽取到人脸的实质特征又能有效减小数据维数,降低NMF分解的复杂性.同时对NMF的基矩阵实施正交化变换,在得到的正交基上进行投影.实验结果表明,该方法对光照变化、表情变化和部分遮罩不敏感,识别性能明显提高.  相似文献   

3.
针对人脸识别中经常遇到的"小样本"和"过学习"等问题,同时为了进一步改善人脸图像的奇异值特征在人脸识别中的识别性能,提出了一种基于奇异值分解和支持向量机的人脸识别新方法.在特征提取阶段,首先对训练样本集中的每一个人脸图像矩阵进行奇异值分解,得到训练样本的奇异值特征,然后对每个样本的奇异值特征向量进行降维、归一化、奇异值向量的分量重新排列等处理.在识别阶段,运用支持向量机作为分类工具,为了提高分类能力,选取径向基函数作为支持向量机的核函数.最后在ORL人脸数据库上验证了该方法.实验结果表明,通过对奇异值特征的相关处理,提高了识别速度和正确识别率.从而证明了所提出方法的有效性,具有一定的应用价值.  相似文献   

4.
提出一种基于小波低频子带的统一特征空间奇异值分解的人脸识别方法.首先利用小波变换提取人脸图像的低频子带,然后作傅立叶变换,获得低频子带的频谱;将低频子带的频谱投影到标准脸奇异值分解的统一特征空间,投影系数作为人脸识别特征;采用L_1距离进行最小距离分类,实验结果表明,该方法比统一特征空间奇异值分解方法可获得更高的识别率.  相似文献   

5.
人脸识别领域中常用Gabor小波系数表示人脸特征.然而,提取的人脸Gabor特征是高维数据,不可避免存在冗余和随机噪声的干扰.为了有效利用Gabor特征进行人脸识别,提出一种新的Gabor特征选取方法.首先计算训练集上的任两张人脸图像的Gabor特征差,生成类内空阃和类外空间.用单个Gabor特征训练筒单两值分类器,以其在类内空间和类外空间的分类错误率作为判据评价该Gabor特征的分类能力.在选取分类错误低的特征的同时还要再评估候选特征与已选特征间的互信息,这样优选出具有无冗余、低误差率的特征.最后对这些优选的Gabor特征进行主成分分析和线性判别分析完成人脸识别.在CAS-PEAL大型人脸数据库上的实验结果表明,所提出的方法不但可大大降低Gabor特征的维数,而且还有效提高了识别精度.  相似文献   

6.
为克服小波变换和Gabor滤波器提取虹膜特征时小波基函数固定和Gabor滤波器参数需优化选择的问题,提出了一种基于经验模态分解(EMD)和奇异值分解(SVD)的虹膜特征提取方法.首先,对预处理后的虹膜图像进行EMD,将获得的一系列固有模态函数和残差分量构成初始矩阵;然后,对该矩阵进行SVD,以其奇异值作为虹膜特征向量:...  相似文献   

7.
针对传统的Gabor小波存在提取特征维数高、识别时间长的缺点,对Gabor小波的使用方法进行了改进.首先利用Gabor小波的幅值直接与人脸图像作乘积得到Gabor图像,接着使用局部二值模式得到纹理图像,然后提取出纹理图像的直方图信息,并作为人脸图像的特征,最后使用支持向量机作为分类器,在未经过预处理的ORL人脸数据库中取得95.0%的识别率.平均每张人脸图像识别时间为0.14 s,表明该算法能符合实际应用的要求.  相似文献   

8.
李孔震 《科学技术与工程》2012,12(29):7616-7620
类估计基空间奇异值分解算法(CSVD)克服了奇异值分解(SVD)造成的重构图像基空间不一致的本质缺陷,但在一定程度上削弱了图像的类别特征。二维非负矩阵分解算法(2DNMF)能在一定程度上避免NMF识别算法中因图像向量化而造成的结构信息丢失、内存花销大等不足,但是随着训练样本数量的增多,迭代速度慢、训练时间长等缺陷也将凸显。根据CSVD与2DNMF的优缺点,提出了人脸识别的联合CSVD-2DNMF算法,进而运用提出的算法在Matlab平台上对ORL人脸数据库中的人脸图像进行了识别实验。实验结果表明该算法能有效的缩短训练时间和提高识别率。  相似文献   

9.
为了改善Gabor滤波器的识别性能,提出了一种自适应的基于Gabor 滤波器的特征权重选择的人脸识别方法. 首先将训练样本进行镜像变换,由镜像偶对称图像构成探测图像集,然后把每幅人脸图像采用离散余弦变化进行降维, 经过Gabor 小波变换提取人脸特征, 再自适应地计算出不同特征对识别的不同贡献并加权到鉴别特征中,最后根据最近邻分类器分类.基于ORL和Yale 人脸库上的实验结果验证了改进算法的有效性.  相似文献   

10.
提出了一种结合Gabor小波变换和二维核判别分析(2DKDA)的新型特征提取方法.算法首先对人脸图像进行Gabor变换,然后通过二维核判别分析进行特征提取,可以很好地保留图像的几何特征和非线性特征.通过在标准人脸数据库上的测试表明,该方法较其他传统的二维特征提取方法具有更高的识别效率.  相似文献   

11.
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.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
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。  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
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.  相似文献   

16.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
19.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

20.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

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