Human gait recognition by the fusion of motion and static spatio-temporal templates

In this paper, we propose a gait recognition algorithm that fuses motion and static spatio-temporal templates of sequences of silhouette images, the motion silhouette contour templates (MSCTs) and static silhouette templates (SSTs). MSCTs and SSTs capture the motion and static characteristic of gait. These templates would be computed from the silhouette sequence directly. The performance of the proposed algorithm is evaluated experimentally using the SOTON data set and the USF data set. We compared our proposed algorithm with other research works on these two data sets. Experimental results show that the proposed templates are efficient for human identification in indoor and outdoor environments. The proposed algorithm has a recognition rate of around 85% on the SOTON data set. The recognition rate is around 80% in intrinsic difference group (probes A-C) of USF data set.     

基于协同表示的步态识别

将基于稀疏表示的分类算法应用于步态识别中,会遇到小样本及计算耗时的问题。针对这一问题,提出一种基于协同表示的步态识别方法。该方法首先通过背景重建、目标提取等处理获得人体侧影轮廓,根据步态轮廓的宽度变化统计步态周期,得到步态能量图GEI;其次,以GEI为基础对测试样本进行协同表示;最后,通过最小重构误差进行识别。实验结果表明,该方法具有较好的识别性能,并且识别时间明显降低。     

Individual recognition using gait energy image

In this paper, we propose a new spatio-temporal gait representation, called gait energy image (GEI), to characterize human walking properties for individual recognition by gait. To address the problem of the lack of training templates, we also propose a novel approach for human recognition by combining statistical gait features from real and synthetic templates. We directly compute the real templates from training silhouette sequences, while we generate the synthetic templates from training sequences by simulating silhouette distortion. We use a statistical approach for learning effective features from real and synthetic templates. We compare the proposed GEI-based gait recognition approach with other gait recognition approaches on USF HumanID Database. Experimental results show that the proposed GEI is an effective and efficient gait representation for individual recognition, and the proposed approach achieves highly competitive performance with respect to the published gait recognition approaches.     

基于LBP和HOG特征分层融合的步态识别

针对步态能量图（GEI）在提取人体信息时只描绘出了轮廓信息,而丢失了内部特征的局限性,提出一种基于人体目标图像的局部二值模式（LBP）与方向梯度直方图（HOG）分层融合的GEI识别算法。该算法步骤包括：首先用光流法提取步态周期,获得一个周期的步态能量图（GEI）;然后分三层提取GEI的LBP特征,得到三层的LBP图像;依次提取每层LBP图像的HOG特征,最后将每层提取的LBP和HOG特征融合,得到每层的新特征;最后将三个新特征依次融合成可以用于识别的最终特征。通过几种方法对CASIA和USF步态数据库的实验对比,提出的算法取得了更高的识别率。     

集成HOG步态模板

步态模板在提升步态识别的实时性能中扮演了关键角色。由于缺乏时间信息和不能充分提取步态中的统计特征,其识别性能会受到一定的损害。以步态能量图（GEI）为模板,并使用基于时间保持的步态能量图（CGI）,从这两个模板中进一步提取空间特征。在此基础上,构造了集成HOG步态模板。这一模板能较好地保持时间信息和有效地提取空间结构特征。在USF步态数据集的实验表明,与其他已知步态识别方法相比,提出的模板实现了好的识别性能。     

General tensor discriminant analysis and gabor features for gait recognition

The traditional image representations are not suited to conventional classification methods, such as the linear discriminant analysis (LDA), because of the under sample problem (USP): the dimensionality of the feature space is much higher than the number of training samples. Motivated by the successes of the two dimensional LDA (2DLDA) for face recognition, we develop a general tensor discriminant analysis (GTDA) as a preprocessing step for LDA. The benefits of GTDA compared with existing preprocessing methods, e.g., principal component analysis (PCA) and 2DLDA, include 1) the USP is reduced in subsequent classification by, for example, LDA; 2) the discriminative information in the training tensors is preserved; and 3) GTDA provides stable recognition rates because the alternating projection optimization algorithm to obtain a solution of GTDA converges, while that of 2DLDA does not.We use human gait recognition to validate the proposed GTDA. The averaged gait images are utilized for gait representation. Given the popularity of Gabor function based image decompositions for image understanding and object recognition, we develop three different Gabor function based image representations: 1) the GaborD representation is the sum of Gabor filter responses over directions, 2) GaborS is the sum of Gabor filter responses over scales, and 3) GaborSD is the sum of Gabor filter responses over scales and directions. The GaborD, GaborS and GaborSD representations are applied to the problem of recognizing people from their averaged gait images.A large number of experiments were carried out to evaluate the effectiveness (recognition rate) of gait recognition based on first obtaining a Gabor, GaborD, GaborS or GaborSD image representation, then using GDTA to extract features and finally using LDA for classification. The proposed methods achieved good performance for gait recognition based on image sequences from the USF HumanID Database. Experimental comparisons are made with nine state of the art classification methods in gait recognition.     

一种基于静态和动态特征的步态识别新方法

最近,利用步态对个人身份进行识别受到越来越多生物识别技术研究者的重视。步态能量图(Gait EnergyImage,GEI)是一种有效的步态表征方法。把步态能量图分解为身体相关能量图(Body-Related GEI,BGEI)、步态相关能量图(Gait-Related GEI,GGEI)、身体步态相关能量图(Body-Gait-Related GEI,BGGEI)3部分,利用傅立叶描绘子对身体相关能量图(BGEI)、身体步态相关能量图(BGGEI)进行描述,利用Gabor小波提取步态相关能量图(GGEI)的幅值特征,分别研究了它们的识别能力,并在Rank层和Score层融合步态相关能量图(GGEI)、身体步态相关能量图(BGGEI)这两部分信息用于步态识别。该算法在CASIA数据库上进行的试验取得了较高的正确识别率。     

基于步态特征提取的ELM身份识别方法

利用步态信息进行身份识别是一种新兴的生物识别技术.相较于其他的生物识别技术,其具有不易伪装、可在远距离情况下进行身份识别的优点.现有模型的识别方法计算量大、模型难以准确建立;现有的分类方法普遍存在训练时间长、分类准确率不高的问题.针对以上问题,对步态视频进行分帧处理,将分帧后的图像进行运动目标检测、形态学处理和图像归一...     

基于时间保持能量图和Radon变换的步态识别

Radon变换把图像从坐标空间映射到Radon空间,因其可以保存频率信息而被应用在步态识别算法中。主要从频率角度入手,着力提高基于Radon变换的步态识别算法的识别正确率,提出了基于时间保持能量图的Radon变换步态识别算法。传统的步态能量图是对步态周期中经过归一化的人体轮廓图求算术平均而得到的步态特征表示,最近提出的时间保持能量图在保持步态能量图的优点的基础上,保留了步态序列的时间信息,在改进的步态周期检测算法的基础上,提出将时间保持能量图和Radon变换结合到一起的步态识别算法。也对结合不同数据空间的特征如频率、形状等做了初步探讨。     

基于嵌入式隐马尔可夫模型的步态识别

针对从多帧步态中更有效提取步态特征的问题,提出了一种基于嵌入式隐马尔可夫模型的步态识别算 法．首先采用背景减除方法提取出人体的侧影轮廓,通过分析轮廓宽度向量的自相关性计算出步态的周期,并得到 平均步态能量图．接着利用二维离散余弦变换获得平均步态能量图的空间特征信息,然后把能量图的观测块转化为 观测向量实现了步态识别．最后运用最近邻法在两个不同的数据库上进行算法验证,实验结果表明该算法具有较好 的识别性能．     

基于SEF-GHEI及协同表示的步态识别研究

将协同表示方法应用于步态识别中可以解决稀疏表示方法计算耗时的问题,但提取步态特征采用的GEI算法没有考虑步态内部轮廓边界信息,导致识别率不高。针对此问题,本文提出使用融合Hog和GEI算法的方法提取步态特征,在此基础上使用协同表示的方法训练,再通过计算测试样本的最小重构误差进行分类。实验结果表明,该方法在单一视角下步态识别准确率平均提高了1.315%,以及跨视角下步态识别准确率平均提高了6.51%,说明本方法是可行的。     

基于模糊主成分分析的步态识别

提出针对步态能量图的基于模糊主成分分析的步态识别算法。通过对原始步态序列进行预处理得到步态能量图,利用模糊主成分分析提取出特征值和对应的特征向量,获得模糊主成分后将其映射到低维空间,并使用最近邻法进行分类。在CASIA数据库上对算法进行验证,实验结果证明,该算法与同类算法相比具有更好的识别性能。     

Integrating face and gait for human recognition at a distance in video.

This paper introduces a new video-based recognition method to recognize noncooperating individuals at a distance in video who expose side views to the camera. Information from two biometrics sources, side face and gait, is utilized and integrated for recognition. For side face, an enhanced side-face image (ESFI), a higher resolution image compared with the image directly obtained from a single video frame, is constructed, which integrates face information from multiple video frames. For gait, the gait energy image (GEI), a spatio-temporal compact representation of gait in video, is used to characterize human-walking properties. The features of face and gait are obtained separately using the principal component analysis and multiple discriminant analysis combined method from ESFI and GEI, respectively. They are then integrated at the match score level by using different fusion strategies. The approach is tested on a database of video sequences, corresponding to 45 people, which are collected over seven months. The different fusion methods are compared and analyzed. The experimental results show that: 1) the idea of constructing ESFI from multiple frames is promising for human recognition in video, and better face features are extracted from ESFI compared to those from the original side-face images (OSFIs); 2) the synchronization of face and gait is not necessary for face template ESFI and gait template GEI; the synthetic match scores combine information from them; and 3) an integrated information from side face and gait is effective for human recognition in video.     

基于迭代切距离原型学习算法的步态识别

作为唯一远程生物认证技术,步态识别一方面越来越受到人们的重视,提出了很多相应的算法,另一方面,它又面临着很多挑战,其难点之一是如何从多帧步态中有效地提取步态特征,针对此问题,并基于步态能量图(GEI)在步态特征表示上的效果,提出了一种迭代切距离原型学习算法,假定各人的步态分布在不同流形上面,首先用切距离改进步态能量图的定义,进而用迭代的方法来解一个最优解问题,从而学习出步态原型图,再通过PCA对步态原形进行特征提取,最后进行识别,证明了该方法的收敛性,实验结果表明所提出的方法取得了比GEl更好的识别率,并证明了步态流形的假设的合理性.     

基于特征点匹配的步态识别

基于图像特征点匹配的算法思想,结合步态能量图(GEI),提出了一种适用于2幅GEI匹配的步态识别方法.在GEI中采用改进的FAST算法提取特征点,并采用具有良好特征描述性能的BRIEF算法描述特征点.考虑到GEI匹配不要求特征点具有旋转不变性,提出了一种质心角约束条件加速特征点的匹配.在CASIA数据库B库上的实验结果表明:方法在识别率和特征计算时间上均具有良好的表现.     

结合非局部与分块特征的跨视角步态识别

目前基于深度学习的步态识别方法大多通过叠加卷积层获取全局特征,忽略有利于细粒度分类的局部特征.针对上述问题,文中提出结合非局部与分块特征的跨视角步态识别方法.将一对步态能量图(GEI)作为输入,提取单样本的非局部信息与样本对之间的相对非局部信息.为了更好地提取局部特征,根据GEI的几何特性,将人体区域水平切分为静态块、微动态块和强动态块,连接至3个二值分类器分别进行训练.在OU-ISIR-LP和CASIA-B步态数据集上的对比实验表明,文中方法的正确识别率较高.     

基于核二维主成分分析算法的步态识别

步态识别是一种新的生物认证技术,它是通过人的行走方式来识别人类身份的方法。为了更加快速有效地对人体步态特征进行提取和识别,采用了基于核二维主成分分析（Kernel two Dimensional Principal Component Analyses,K2DPCA）的方法进行步态特征提取,运用支持向量机（SVM）进行步态识别。根据人体步态下肢摆动距离统计出步态周期,得到步态能量图（GEI）,对生成的GEI采用核二维主成分分析方法进行步态特征向量提取,采用SVM分类器进行分类识别。实验结果表明该方法具有很好的识别效果。     

对步态空时数据的连续特征子空间分析

提出一种基于空时特征提取的人体步态识别算法。连续的特征子空间学习依次提取出步态的时间与空间特征：第一次特征子空间学习对步态的频域数据进行主成分分析,步态数据被转化为周期特征矢量;第二次特征子空间学习对步态数据的周期特征矢量形式进行主成分分析加线性判别分析的联合分析,步态数据被进一步转化为步态特征矢量。步态特征矢量同时包含运动的周期特征以及人体的形态特征,具有很强的识别能力。在USF步态数据库上的实验结果显示,该算法识别率较其他同类算法有明显提升。     

一种步态识别方法

步态识别作为一种新的生物特征识别技术,通过人走路的姿势实现对个人身份的识别和认证.算法利用步态轮廓图像边界到重心的距离矢量对步态轮廓图像进行描述,采用步态图像的高宽比进行步态的准周期性分析.利用隐马尔可夫模型进行步态时变数据匹配识别.算法在CMU数据库上面进行实验取得了较高的正确识别率.