基于动态主成分子空间的人脸识别算法

在基于子空间分析的人脸识别中,通常是按照特征值的大小来确认主成分的重要性,并以此为基础构造一个固定的特征子空间.通过人脸图像重建分析,发现固定的特征子空间会给人脸识别带来误差,于是采用多元线性回归分析理论,提出一个动态主成分子空间构造算法.在此基础上,得到了动态PCA(主成分分析)算法和基于Gabor特征的动态PCA算法.由ORL和Georgia Tech人脸数据库上的实验结果表明,该算法不仅减少了主成分数目,而且提高了识别率.     

数字图像识别在人脸检测中的应用

利用数字图像模式识别技术实现了人脸的自动检测及特征定位.对数字图像处理中的颜色模型、肤色建模的原理及在人脸识别中的应用进行了概述,分析了人脸识别过程中存在的困难,展望了人脸识别技术的发展方向.     

一种基于支持向量机的人脸识别新方法

关于人脸识别问题,采用一种基于独立分量分析进行特征提取和支持向量机实现多分类的人脸识别新方法.根据支持向量机理论,为提高对人脸的识别率,提出环形对称划分的支持向量机多分类算法.算法将多类问题的类别环形排列,依次进行对称划分构造纠错编码输出矩阵;根据求得的纠错编码输出矩阵,用解码函数求解待求样本的类别.对于人脸识别问题,利用独立分量分析方法构造人脸的特征脸空间,在特征脸空间运用算法进行人脸识别,在人脸数据库上的仿真结果表明,算法能有效地完成人脸识别任务.     

基于核独立成分分析的人脸识别研究

在人脸识别中提出一种基于非线性子空间的核独立成分分析(KICA)方法。在简单介绍了ICA方法的基础上,对KICA方法的基本原理和算法作了较为详细的描述。为了验证基于KICA和ICA的人脸识别方法的识别效果,进行了对比实验和分析。实验和分析结果表明,在人脸识别中,基于KICA的方法优于基于ICA的方法。     

基于模糊隶属度函数的ICA特征提取和识别

提出了一种基于模糊隶属度函数的独立成分分析图像特征提取和识别方法.该方法首先通过主成分分析等对图像进行预处理,然后通过FastICA算法对图像进行处理,构造特征脸子空间,计算训练样本和待测样本在特征脸子空间中的投影,引入模糊隶属度函数,建立矢量隶属度函数,作为识别分类器进行人脸识别.针对ORL标准人脸数据库上的实验结果表明,该方法具有良好的识别分类能力.     

基于特征加权的人脸识别

现有的人脸识别方法通常未考虑不同特征或像素对识别结果的影响。实际上,人脸面部不同特征在人脸识别过程中的作用是不同的。研究了各个特征在识别中的作用,分别采用三种加权方法对人脸图像进行了预处理,并应用流行的人脸识别方法（联想记忆、主分量分析和Fisher线性判别分析）进行识别。最后用标准人脸库ORL进行了实验,实验结果表明特征加权方法对人脸识别是有效且通用的。     

基于外观的子空间人脸识别方法研究*

研究了最常使用的三种基于外观的人脸识别子空间统计方法,分析比较了三种方法的理论和各种实验结果,并对其进行了总结.     

自适应半监督边界费舍尔分析

基于图的半监督算法已经成功地应用于人脸识别中,算法不仅考虑带标签数据而且利用一致性的假设。传统的算法一致性约束是定义在原特征空间中,但是在原特征空间中定义的一致性不是最好的。提出了自适应半监督边界费舍尔分析算法,它将一致性约束定义在原特征空间和期望低维特征空间中。在CMU PIE和YALE-B数据库上进行了实验,结果表明自适应半监督边界费舍尔分析算法在人脸识别率上有显著的提高。     

基于MobileNetV2与树莓派的人脸识别系统

人脸识别技术在安防,商业,金融等领域都有广泛的应用.针对目前人脸识别系统成本高,易用性低等现象,提出了基于树莓派(Raspberry Pi)实现人脸识别的方案.首先利用OpenCV计算机视觉库中的Harr级联方法,对图像中的人脸进行定位;然后利用改进的MobileNetV2网络模型对人脸进行特征提取和分类,得到一个优化的人脸识别模型;最后将模型移植到Raspberry Pi进行人脸识别.该模型对图库中的人识别准确率为95％,对陌生人识别准确率为80％.实验结果表明该系统进行人脸识别工作稳定,识别速度快,应用场景广.     

基于神经网络的快速核子空间人脸识别算法研究

针对现有核子空间人脸识别算法计算量大且速度缓慢的现状,提出了一种基于神经网络的快速核子空间人脸识别算法模型,利用神经网络的隐含层神经元将核特征子空间的基表示进行约减,从而大幅提高了识别速度。进而基于KPCA和KFDA两种核子空间人脸识别算法,建立了神经网络逼近模型,并基于ORL、UMIST和YALE 3种人脸数据库进行了实证分析。实验结果表明,当隐含层神经元个数设置为训练样本总数一半或更少时,基于神经网络的快速核子空间算法能够取得相近甚至相当于核子空间算法的识别率。从而在满足一定识别正确率的条件下,能将识别时间缩短到50%甚至更低。     

Kernel-based nonlinear discriminant analysis for face recognition

Linear subspace analysis methods have been successfully applied to extract features for face recognition.But they are inadequate to represent the complex and nonlinear variations of real face images,such as illumination,facial expression and pose variations,because of their linear properties.In this paper,a nonlinear subspace analysis method,Kernel-based Nonlinear Discriminant Analysis (KNDA),is presented for face recognition,which combines the nonlinear kernel trick with the linear subspace analysis method-Fisher Linear Discriminant Analysis (FLDA).First,the kernel trick is used to project the input data into an implicit feature space,then FLDA is performed in this feature space.Thus nonlinear discriminant features of the input data are yielded.In addition,in order to reduce the computational complexity,a geometry-based feature vectors selection scheme is adopted.Another similar nonlinear subspace analysis is Kernel-based Principal Component Analysis (KPCA),which combines the kernel trick with linear Principal Component Analysis (PCA).Experiments are performed with the polynomial kernel,and KNDA is compared with KPCA and FLDA.Extensive experimental results show that KNDA can give a higher recognition rate than KPCA and FLDA.     

基于张量分析的表情特征提取

表情识别的性能依赖于所提取表情特征的有效性,现有方法提取的表情基本上是人脸与表情的融合体,然而不同个体的人脸差异是表情识别的主要干扰因素。在表情识别时,理想情况是将个体相关的人脸特征和与个体无关的表情特征相分离。针对此问题,在三维空间建立人脸张量;然后用张量分析的方法将人脸特征与表情特征进行分离,使获取的表情参数与人脸无关。从而排除不同个体的人脸差异对表情识别的干扰。最后,在JAFFE表情数据库上验证了该方法的有效性。     

基于双邻接图正交近邻保持投影的人脸识别算法

正交保持投影(ONPP)是经典的图嵌入降维技术,已经成功地应用到人脸识别中,其保持了高维数据的局部性和整体几何结构。监督的ONPP通过建立同类邻接图来最小化同类局部重构误差,寻找最优的低维嵌入,但是其只使用了类内信息,这会导致异类数据点间的结构不够明显。因此,提出了基于双邻接图的正交近邻保持投影(DAG-ONPP)算法。通过建立同类邻接图与异类邻接图,在数据嵌入低维空间后同类近邻重构误差尽量小,异类近邻重构误差更加明显。在ORL,Yale,YaleB和PIE人脸库上的实验结果表明,与其他经典算法相比,所提方法有效提高了分类能力。     

Multi-view face recognition based on tensor subspace analysis and view manifold modeling

This paper aims to address the face recognition problem with a wide variety of views. We proposed a tensor subspace analysis and view manifold modeling based multi-view face recognition algorithm by improving the TensorFace based one. Tensor subspace analysis is applied to separate the identity and view information of multi-view face images. To model the nonlinearity in view subspace, a novel view manifold is introduced to TensorFace. Thus, a uniform multi-view face model is achieved to deal with the linearity in identity subspace as well as the nonlinearity in view subspace. Meanwhile, a parameter estimation algorithm is developed to solve the view and identity factors automatically. The new face model yields improved facial recognition rates against the traditional TensorFace based method.     

Supervised Discriminant Projection with Its Application to Face Recognition

In the past few decades, many face recognition methods have been developed. Among these methods, subspace analysis is an effective approach for face recognition. Unsupervised discriminant projection (UDP) finds an embedding subspace that preserves local structure information, and uncovers and separates embedding corresponding to different manifolds. Though UDP has been applied in many fields, it has limits to solve the classification tasks, such as the ignorance of the class information. Thus, a novel subspace method, called supervised discriminant projection (SDP), is proposed for face recognition in this paper. In our method, the class information was utilized in the procedure of feature extraction. In SDP, the local structure of the original data is constructed according to a certain kind of similarity between data points, which takes special consideration of both the local information and class information. We test the performance of the proposed method SDP on three popular face image databases (i.e. AR database, Yale database, and a subset of FERET database). Experimental results show that the proposed method is effective.     

An Analysis of Linear Subspace Approaches for Computer Vision and Pattern Recognition

Linear subspace analysis (LSA) has become rather ubiquitous in a wide range of problems arising in pattern recognition and computer vision. The essence of these approaches is that certain structures are intrinsically (or approximately) low dimensional: for example, the factorization approach to the problem of structure from motion (SFM) and principal component analysis (PCA) based approach to face recognition. In LSA, the singular value decomposition (SVD) is usually the basic mathematical tool. However, analysis of the performance, in the presence of noise, has been lacking. We present such an analysis here. First, the “denoising capacity” of the SVD is analysed. Specifically, given a rank-r matrix, corrupted by noise—how much noise remains in the rank-r projected version of that corrupted matrix? Second, we study the “learning capacity” of the LSA-based recognition system in a noise-corrupted environment. Specifically, LSA systems that attempt to capture a data class as belonging to a rank-r column space will be affected by noise in both the training samples (measurement noise will mean the learning samples will not produce the “true subspace”) and the test sample (which will also have measurement noise on top of the ideal clean sample belonging to the “true subspace”). These results should help one to predict aspects of performance and to design more optimal systems in computer vision, particularly in tasks, such as SFM and face recognition. Our analysis agrees with certain observed phenomenon, and these observations, together with our simulations, verify the correctness of our theory.     

ICA-based neighborhood preserving analysis for face recognition

We present a new dimensionality reduction method for face recognition, which is called independent component based neighborhood preserving analysis (IC-NPA). In this paper, NPA is firstly proposed which can keep the strong discriminating power of LDA while preserving the intrinsic geometry of the in-class data samples. As NPA depends on the second-order statistical structure between pixels in the face images, it cannot find the important information contained in the high-order relationships among the image pixels. Therefore, we propose IC-NPA method which combines ICA and NPA. In this method, NPA is performed on the reduced ICA subspace which is constructed by the statistically independent components of face images. IC-NPA can fully consider the statistical property of the input feature. Furthermore, it can find an embedding that preserves local information. In this way, IC-NPA shows more discriminating power than the traditional subspace methods when dealing with the variations resulting from changes in lighting, facial expression, and pose. The feasibility of the proposed method has been successfully tested on both frontal and pose-angled face recognition, using two data sets from the FERET database and the CAS-PEAL database, respectively. The experiment results indicate that the IC-NPA shows better performance than the popular method, such as the Eigenface method, the ICA method, the LDA-based method and the Laplacianface method.     

局部非参数子空间分析在人脸识别中的应用

提出了一种局部非参数子空间分析算法（Local Nonparametric Subspace Analysis,LNSA）,将其应用在人脸识别中。LNSA算法结合了非参数子空间算法（Nonparametric Subspace Analysis,NSA）与局部保留投影算法（Locality Preserving Projection,LPP）。它利用LPP算法中的相似度矩阵重构NSA的类内散度矩阵,使得在最大化类间散度矩阵的同时保留了类的局部结构。在ORL人脸库和XM2VTS人脸库上作了实验并证明LNSA方法要优于其他方法。     

Robust large margin discriminant tangent analysis for face recognition

Fisher’s Linear Discriminant Analysis (LDA) has been recognized as a powerful technique for face recognition. However, it could be stranded in the non-Gaussian case. Nonparametric discriminant analysis (NDA) is a typical algorithm that extends LDA from Gaussian case to non-Gaussian case. However, NDA suffers from outliers and unbalance problems, which cause a biased estimation of the extra-class scatter information. To address these two problems, we propose a robust large margin discriminant tangent analysis method. A tangent subspace-based algorithm is first proposed to learn a subspace from a set of intra-class and extra-class samples which are distributed in a balanced way on the local manifold patch near each sample point, so that samples from the same class are clustered as close as possible and samples from different classes will be separated far away from the tangent center. Then each subspace is aligned to a global coordinate by tangent alignment. Finally, an outlier detection technique is further proposed to learn a more accurate decision boundary. Extensive experiments on challenging face recognition data set demonstrate the effectiveness and efficiency of the proposed method for face recognition. Compared to other nonparametric methods, the proposed one is more robust to outliers.     

Face recognition based on dictionary learning and subspace learning

Dictionary learning plays an important role in sparse representation based face recognition. Many dictionary learning algorithms have been successfully applied to face recognition. However, for corrupted data because of noise or face variations (e.g. occlusion and large pose variation), their performances decline due to the disparity between domains. In this paper, we propose a face recognition algorithm based on dictionary learning and subspace learning (DLSL). In DLSL, a new subspace learning algorithm (SL) is proposed by using sparse constraint, low-rank technology and our label relaxation model to reduce the disparity between domains. Meanwhile, we propose a high-performance dictionary learning algorithm (HPDL) by constructing the embedding term, non-local self-similarity term, and time complexity drop term. In the obtained subspace, we use HPDL to classify these mapped test samples. DLSL is compared with other 28 algorithms on FRGC, LFW, CVL, Yale B and AR face databases. Experimental results show that DLSL achieves better performance than those 28 algorithms, including many state-of-the-art algorithms, such as recurrent regression neural network (RRNN), multimodal deep face recognition (MDFR) and projective low-rank representation (PLR).