基于小波变换和支持向量机的步态识别算法

为了快速准确地进行人体运动步态识别,基于运动人体的轮廓宽度特征,提出了一种新的步态识别算法。该算法首先对每个序列进行运动轮廓抽取,同时从3个方向(水平、垂直、斜向)对时变的2维轮廓进行投影扫描,并分别转换为对应的特征向量;然后通过对级联的特征向量进行离散正交小波变换来提取低维步态特征,并抑制噪声;在此基础上采用支持向量机训练步态分类器组,最后用支持向量机组进行步态识别。在一组30人构成的步态数据库中进行的实验结果表明,该算法具备快速、稳健的特征,识别率达到91%,初步具备了实际应用的价值。     

一种改进的基于地面反作用力的步态识别方法

提出一种改进的基于地面反作用力的步态识别方法．该方法通过由三维测力台构建的步态通道获取步行时足底受到的三方向地面反作用力,并采用小波包分解提取时频域特征,利用模糊C 均值聚类算法从中挑选出最具分类能力的特征子集,最后在训练样本上用支持向量机训练分类器,并在测试集上进行步态识别．为提高识别率,对样本进行拆分和波形对齐操作,并设计多分类器以降低步行速度变化对识别准确率的影响．在103人的步态数据库上的测试结果表明,该方法即使在训练样本较少的情况下也可以得到较高的识别率．     

基于视频残差神经网络的深度步态识别

步态识别是根据人体的行走方式进行身份识别. 目前, 大多数步态识别方法通过浅层神经网络进行特征提取, 在室内步态数据集表现良好, 然而在近年新公布的室外步态数据集中性能表现不佳. 为了解决室外步态数据集带来的严峻挑战, 提出了一种基于视频残差神经网络的深度步态识别模型. 在特征提取阶段, 基于提出的视频残差块构建深层3D卷积神经网络(3D CNN), 提取整个步态序列的时空动力学特征; 然后, 引入时序池化和水平金字塔映射降低采样特征分辨率并提取局部步态特征; 使用联合损失函数驱动训练过程, 最后通过BNNeck平衡损失函数并调整特征空间. 实验分别在公开的室内 (CASIA-B)、室外(GREW、Gait3D)这3个步态数据集上进行. 实验结果表明, 该模型在室外步态数据集中的准确率以及收敛速度优于其他模型.     

基于Tsfresh-RF特征提取的人体步态识别算法

惯性传感器(IMU)由于尺寸小、价格低、精度高以及信息实时性强等优点, 在人体运动信息的获取与控制等方面得到广泛应用, 但在步态识别的时间序列特征提取和步态环境数据等方面还存在着明显的局限. 本文针对人体下肢步态识别特征提取的复杂性及适用性差等问题, 提出基于Tsfresh-RF特征提取的人体步态识别新方法. 首先, 利用IMU获取的人体步态数据集, 构建基于Tsfresh时间序列特征提取和随机森林(RF)的人体步态识别算法模型. 其次, 采用该算法对人体不同传感器位置进行实验, 完成爬梯、行走、转弯等9种人体运动步态的识别. 最后, 实验结果表明所提方法平均分类准确率达到91.0％, 显著高于传统的支持向量机(SVM)与朴素贝叶斯(NB)等方法的识别结果. 此外, 本文所提基于Tsfresh-RF特征提取的人体步态识别算法具有很好的鲁棒性, 将为后续下肢外骨骼机器人的控制提供有利依据.     

基于足底压力与支持向量机的步态相位识别研究

随着两足机器人、人工假肢技术以及为行走困难病人康复设计的康复训练机器人的发展,在线的步态相位识别方法越来越重要。本文提出的基于足底压力与支持向量机(SVM)的步态相位识别算法主要由五部分组成,即数据采集、数据预处理、特征提取、训练分类器和分类识别。实验表明：该方法能够对运动中的步态相位进行准确的判断。     

基于SVM的步态识别方法综述

步态识别是非接触式生物特征识别领域的前沿课题,通过对人体行走方式的识别以确定个体的身份,在智能视频监控领域有较高的研究价值.步态分类是步态识别过程中的重要任务和关键步骤.首先概述了步态识别过程及分类方法,然后重点对基于支持向量机的步态分类方法进行了综述,分析了基于该方法的最新研究进展,对每个具体研究方法的优缺点进行了对比.最后,指出目前步态识别在实际应用中存在的局限性,并对该领域发展方向进行了展望.     

基于模糊支持向量机的步态识别

提出基于模糊支持向量机（FSVM）的步态识别方法,以人体步态的宽度向量作为特征,探讨直接取值法和模糊C均值2种模糊隶属度确定方法对FSVM步态分类效果的影响。实验结果表明,模糊C均值法的识别率均略好于SVM,直接取值法的识别率甚至低于SVM,因此,选取正确的模糊隶属度确定方法是FSVM能否成功应用于步态识别的关键。     

Improved gait recognition by multiple-projections normalization

Recognizing people by gait promises to be useful for identifying individuals from a distance; in this regard, improved techniques are under development. In this paper, an improved method for gait recognition is proposed. Binarized silhouette of a motion object is first represented by four 1-D signals that are the basic image features called the distance vectors. The distance vectors are differences between the bounding box and silhouette, and extracted using four projections to silhouette. Fourier Transform is employed as a preprocessing step to achieve translation invariant for the gait patterns accumulated from silhouette sequences that are extracted from the subjects’ walk in different speed and/or different time. Then, eigenspace transformation is applied to reduce the dimensionality of the input feature space. Support vector machine (SVM)-based pattern classification technique is then performed in the lower-dimensional eigenspace for recognition. The input feature space is alternatively constructed by using two different approaches. The four projections (1-D signals) are independently classified in the first approach. A fusion task is then applied to produce the final decision. In the second approach, the four projections are concatenated to have one vector and then pattern classification with one vector is performed in the lower-dimensional eigenspace for recognition. The experiments are carried out on the most well-known public gait databases: the CMU, the USF, SOTON, and NLPR human gait databases. To effectively understand the performance of the algorithm, the experiments are executed and presented as increasing amounts of the gait cycles of each person available during the training procedure. Finally, the performance of the proposed algorithm is comparatively illustrated to take into consideration the published gait recognition approaches.     

红外图像中基于混合特征的步态识别方法

针对夜间行人的身份识别问题,结合步态轮廓形状特征及模型投影特征,提出一种红外图像中的混合步态识别方法。采用Radon变换获取步态图像的形状特征,建立3D自适应人体模型,给出基于3D模型的跟踪方法,以获得步态模型特征,并利用SVM进行分类。实验结果表明,该方法具有一定的鲁棒性,识别率可达95.28%。     

Silhouette analysis-based gait recognition for human identification

Human identification at a distance has recently gained growing interest from computer vision researchers. Gait recognition aims essentially to address this problem by identifying people based on the way they walk. In this paper, a simple but efficient gait recognition algorithm using spatial-temporal silhouette analysis is proposed. For each image sequence, a background subtraction algorithm and a simple correspondence procedure are first used to segment and track the moving silhouettes of a walking figure. Then, eigenspace transformation based on principal component analysis (PCA) is applied to time-varying distance signals derived from a sequence of silhouette images to reduce the dimensionality of the input feature space. Supervised pattern classification techniques are finally performed in the lower-dimensional eigenspace for recognition. This method implicitly captures the structural and transitional characteristics of gait. Extensive experimental results on outdoor image sequences demonstrate that the proposed algorithm has an encouraging recognition performance with relatively low computational cost.     

Human action recognition using three orthogonal planes with unsupervised deep convolutional neural network

Deep learning models have attained great success for an extensive range of computer vision applications including image and video classification. However, the complex architecture of the most recently developed networks imposes certain memory and computational resource limitations, especially for human action recognition applications. Unsupervised deep convolutional neural networks such as PCANet can alleviate these limitations and hence significantly reduce the computational complexity of the whole recognition system. In this work, instead of using 3D convolutional neural network architecture to learn temporal features of video actions, the unsupervised convolutional PCANet model is extended into (PCANet-TOP) which effectively learn spatiotemporal features from Three Orthogonal Planes (TOP). For each video sequence, spatial frames (XY) and temporal planes (XT and YT) are utilized to train three different PCANet models. Then, the learned features are fused after reducing their dimensionality using whitening PCA to obtain spatiotemporal feature representation of the action video. Finally, Support Vector Machine (SVM) classifier is applied for action classification process. The proposed method is evaluated on four benchmarks and well-known datasets, namely, Weizmann, KTH, UCF Sports, and YouTube action datasets. The recognition results show that the proposed PCANet-TOP provides discriminative and complementary features using three orthogonal planes and able to achieve promising and comparable results with state-of-the-art methods.

     

Gait recognition using multi-bipolarized contour vector

Gait recognition has recently attracted increasing interest from the biometric community. In this paper, we propose a simple yet powerful new feature called multi-bipolarized contour vector (MBCV) for gait recognition. The proposed MBCV feature consists of four components: (1) the Vertical Positive Contour Vector, (2) the Vertical Negative Contour Vector, (3) the Horizontal Positive Contour Vector, and (4) the Horizontal Negative Contour Vector. We furthermore develop a gait recognition system based on the proposed MBCV feature. The system consists of three steps: image preprocessing including background subtraction and silhouette normalization, extraction of the MBCV feature, and classification. To reduce the dimensionality of MBCV, we use principal component analysis (PCA). To solve the classification problem, we use the Euclidean distance and a nearest neighbor (NN) approach. Finally, we fuse the proposed gait features at all levels to improve recognition performance. The proposed recognition system is applied to the well-known NLPR gait database and its effectiveness is demonstrated via comparison with previous works.     

基于角度特征分量特征的步态识别

目前,在步态识别技术中多数描述步态特征的方法在非侧面视角下识别效果一般都不够理想,通常会明显低于侧面视角,针对这一问题,文章提出一种以角度特征分量特征作为步态特征的识别方法,提高步态特征的分类能力从而提高识别率。在步态检测部分文章采用基于色度坐标的混合高斯来抑制阴影和消除噪声,步态识别部分使用支持向量机对所提取的角度特征分量特征进行训练和分类,最终在保证侧面视角识别率的情况下同时提高在非侧面视角下的识别效果。     

基于融合特征与支持向量机的控制图模式识别

为了提高控制图模式识别的精度, 将控制图模式的原始特征与形状特征相融合得到分类特征, 并采用支持向量机进行模式分类的控制图模式识别。融合所得特征既保持了控制图模式的原始特征所蕴涵的模式全局特性信息, 又通过引入形状特征对部分易混淆模式的局部几何特性进行强化, 使不同模式间的区分度得到有效提高; 而以支持向量机作为模式分类器保证方法在高维度特征和小样本条件下也能获得较好的识别性能。仿真实验结果表明所提方法的识别精度相比其他几种基于形状特征的控制图模式识别方法有明显提高。     

基于步态的身份识别

提出了一种简单有效的自动步态识别算法，对于每个序列而言，一种改进的背景减除方法用于检测行人的运动轮廓，然后，这些时变的2D轮廓形状被转换为对应的1D距离信号，同时通过特征空间变换来提取低维步态特征，基于时空相关或归一化欧氏距离度量，标准的模式分类技术用于最终的识别，实验结果表明该算法不仅获得了令人鼓舞的识别性能，而且拥有相对较低的计算代价。     

采用精选Gabor小波和SVM分类的物体识别

提出了一种基于Gabor小波和支持向量机的物体识别通用框架. 在该框架中, 特征抽取采用选取的Gabor小波在物体的最佳位置卷积实现, 而分类则通过支持向量机实现. 相比传统的基于Gabor特征的识别系统, 该方法能够同时达到准确而快速的分类目的. 本论文成功地将该框架应用于两个实际的物体识别例子: 物体/非物体分类和人脸识别. 实验结果证明了所提出的方法相对于其它方法的优越性.     

Neural computing for walking gait pattern identification based on multi-sensor data fusion of lower limb muscles

The use of neural computing for gait analysis widely known as computational intelligent gait analysis is addressed recently. This research work reports multilayer feed-forward neural networks for walking gait pattern identification using multi-sensor data fusion; electromyography (EMG) signals and soft tissue deformation analysis using successive frames of video sequence extracted from lower limb muscles according to each gait phase within the considered gait cycle. Neural computing framework for walking gait pattern identification consists of system hardware and intelligent system software. System hardware comprises a wireless surface EMG sensor unit and two video cameras for measuring the neuromuscular activity of lower limb muscles, and a custom-developed artificial neural network for classifying the gait patterns of subjects during walking. The system uses root mean square and soft tissue deformation parameter as the input features. Multilayer feed-forward back propagation neural networks (FFBPNNs) with different network training functions were designed, and their classification results were compared. The intelligent gait analysis system validation has been carried out for a group of healthy and injured subjects. The results demonstrated that the overall accuracy of 98 % prediction is achieved for gait patterns classification established by multi-sensor data fusion of lower limb muscles using FFBPNN with Levenberg–Marquardt training function resulting better performance over FFBPNN with other training functions.

     

Difference intensity distance group pattern for recognizing actions in video using Support Vector Machines

Recognition of human actions is a very important, task in many applications such as Human Computer Interaction, Content based video retrieval and indexing, Intelligent video surveillance, Gesture Recognition, Robot learning and control, etc. An efficient action recognition system using Difference Intensity Distance Group Pattern (DIDGP) method and recognition using Support Vector Machines (SVM) classifier is presented. Initially, Region of Interest (ROI) is extracted from the difference frame, where it represents the motion information. The extracted ROI is divided into two blocks B1 and B2. The proposed DIDGP feature is applied on the maximum intensity block of the ROI to discriminate the each action from video sequences. The feature vectors obtained from the DIDGP are recognized using SVM with polynomial and RBF kernel. The proposed work has been evaluated on KTH action dataset which consists of actions like walking, running, jogging, hand waving, clapping and boxing. The proposed method has been experimentally tested on KTH dataset and an overall accuracy of 94.67% for RBF kernel.     

基于人体轮廓宽度特征的步态识别

基于人体轮廓宽度特征提出了一种步态识别算法。首先对每个序列进行运动轮廓抽取,将这些时变的二维轮廓形状转换为对应的一维横向宽度信号,通过主元分析法(PCA)来提取低维步态特征,在此基础上采用线性判决分析(LDA),以获取最佳投影方向,达到提高数据分类能力的目的。在NLPR、CMU和UMF步态数据库中进行实验,结果表明算法具备快速、稳健特征,在实际应用中具备较大的价值。