基于连续隐马尔可夫模型的步态识别

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数据库上进行实验取得了较高的正确识别率.     

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.     

基于人体动静态特征融合的步态识别算法研究

提出一种融合步态运动中人体的静态特征和动态特征的步态识别算法:利用背景减除法得到人体轮廓,通过轮廓图像分段距离来表示静态特征;采用步态图像两脚的步幅和步频来表示动态特征;然后对两种特征进行加法融合、最小值融合、最大值融合和Choquet模糊积分融合。实验表明,两种特征融合后的性能优于基于单个特征步态识别算法,融合后识别率提高了5%到10%。     

基于傅立叶描绘子的步态识别

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。利用傅立叶描绘子对步态轮廓图像进行描述，用步态图像的高宽比进行步态的准周期性分析，并采用动态时间规正算法解决不同的步态周期的图像序列之间的比较问题。该算法在CMU数据库上面进行试验取得了较高的正确识别率。     

基于角度直方图的步态识别算法

本文提出了一种简单实用的步态识别算法.该算法使用背景减除的方法检测人的运动区域;然后统计运动区域上像素的角度直方图,提取角度直方图向量作为步态特征;以欧氏距离作为度量,使用标准模式分类器用于步态识别.实验结果表明,本文提出的算法识别性能较高,并具有计算代价小等优点.     

新的基于特征关系表述的步态识别算法

为了快速有效地进行步态识别,利用特征关系非平稳分布的统计特性,提出了一种新的基于特征关系表述的步态识别算法。首先,将剪影轮廓相邻像素点间8邻域相对方向标号作为特征关系属性一,将轮廓边界点与中心点间的距离作为特征关系属性二,经直方图归一化处理,得到两种关系属性的联合概率;其次,结合主成分分析(PCA)降维的方法,提取特征主向量;最后,采用最近邻分类器进行识别分类。实验证明,该算法在CASIA步态数据库上,最高达到了90%以上的识别率,而且与传统的特征关系表述步态识别算法相比,关系属性联合概率矩阵维数由900维下降到240维,大大降低了算法的计算代价。     

基于特征融合的步态识别算法研究*

提出一种融合步态运动中的人体形状信息特征和下肢运动信息特征的步态识别算法：利用边界跟踪算法获取人体轮廓边界线,并采用傅里叶描述子表达人体轮廓特征;依据人体解剖学的知识定位下肢关节点,并提取下肢角度特征;分别对两种特征进行匹配,然后采用特征融合的方法对匹配结果进行处理。实验结果表明,本算法的性能较基于单个特征的步态识别算法有明显的改善。     

基于统一Hu和支持向量机的步态识别

为了快速准确地进行人体运动步态识别,基于人体轮廓统一Hu矩的不变矩特征,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提取,然后计算每个序列的不变矩,构成步态特征空间;在此基础上采用支持向量机训练步态,最后用支持向量机进行步态识别。实验结果表明,该算法具备快速、稳健的特征,取得了较好的识别率,初步具备了实际应用的价值。     

基于不变矩特征和神经网络的步态识别

步态识别是利用人体步行的方式来识别人的身份.近年来,步态作为一种生物特征识别技术已引起越来越多人们的兴趣.本文提出了一种简单有效的步态识别算法,首先通过背景差方法得到运动人体轮廓,然后利用不变矩描述轮廓特征,最后用BP神经网络方法来进行模板匹配,实现人的身份识别.     

基于特征融合的步态识别算法

步态运动中包含人体形状信息和运动信息,目前步态识别算法多数基于单一信息,不能取得满意的识别结果。利用特征融合的思想,提出一种融合人体轮廓特征和下肢角度特征的步态识别算法。采用傅立叶描述子描述人体轮廓特征;区别于基于模型的运动特征提取方法,依据人体解剖学的知识获取下肢角度,计算代价较小;采用加权融合规则实现两类特征的融合。仿真结果表明,本算法的性能较基于单个特征的算法有明显的提高。     

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.     

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.     

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．     

能量图空间分解法和DSW相结合的步态识别

提出一种能量图空间分解法和DSW（动态空间规整法）相结合的步态识别算法;提取二值化步态轮廓序列,通过计算差分图像获取步态序列的活动能量图,在空间域进行行列分解;通过加窗和傅里叶变化等对分解向量进行频谱分析,并对频谱曲线求极值来构建步态特征向量;采用DSW算法,进行空间领域的步态分类识别。使用中科院自动化研究所的Dataset B数据库进行了充足的实验,最终的平均识别率达到了93%,并对衣服背包具有较强的鲁棒性,与其他相关文献的对比显示该算法具有更好的识别性能。     

一种基于模型的步态识别方法

该文提出了一种简单有效的基于人体骨骼化模型的步态识别方法。首先,对输入的步态序列自动进行背景初始化;然后分割图像中运动人体的侧面影像,并进一步细化为人体的骨骼化模型;从模型中提取人体的静态参数(如身高、步幅)以及动态参数(如运动过程中关节点的位置、肢体角度);最后,应用标准的模式分类技术对个体的身份做出识别。实验结果表明,此方法通过提取可靠的步态特征,降低了数据处理的代价,而且得到了较为良好的识别性能。     

Effect of silhouette quality on hard problems in Gait recognition.

Gait as a behavioral biometric has been the subject of recent investigations. However, understanding the limits of gait-based recognition and the quantitative study of the factors effecting gait have been confounded by errors in the extracted silhouettes, upon which most recognition algorithms are based. To enable us to study this effect on a large population of subjects, we present a novel model based silhouette reconstruction strategy, based on a population based hidden Markov model (HMM), coupled with an eigen-stance model, to correct for common errors in silhouette detection arising from shadows and background subtraction. The model is trained and benchmarked using manually specified silhouettes for 71 subjects from the recently formulated HumanID Gait Challenge database. Unlike other essentially pixel-level silhouette cleaning methods, this method can remove shadows, especially between feet for the legs-apart stance, and remove parts due to any objects being carried, such as briefcase or a walking cane. After quantitatively establishing the improved quality of the silhouette over simple background subtraction, we show on the 122 subjects HumanID Gait Challenge Dataset and using two gait recognition algorithms that the observed poor performance of gait recognition for hard problems involving matching across factors such as surface, time, and shoe are not due to poor silhouette quality, beyond what is available from statistical background subtraction based methods.     

A framework for online gait recognition based on multilinear tensor analysis

The gait recognition is to recognize an individual based on the characteristics extracted from the gait image sequence. There are many researches for the gait recognition which use diverse kinds of information such as shape of gait silhouette, motion variation caused by walking, and so on. In general, shape information is more useful for recognition. However, shape information is influenced by a variety of factors, which degrade the recognition performance. Moreover, the information used in most of those studies might be able to be extracted after all of one or more sequences of the gait cycle are known. And it is also hard to discriminate the gait cycle from given gait sequences exactly by the online approach. In regard to these difficulties, we propose a novel gait recognition method based on the multilinear tensor analysis. To recognize the cyclic characteristic of gait without an exact division for the gait cycle, this paper’s propose is the method to form the accumulated silhouette and then describes those as the tensor. For the accumulated silhouette proposed by this paper, the image sequence of one gait cycle is divided into four sections in the training phase. However, discrimination for the gait cycle in the training phase is not directly related to the recognition phase, thus the online approach is possible. We first form the accumulated silhouettes for every individual using gait silhouettes within each section. And then, we represent these accumulated silhouettes as the tensor. Using a multilinear tensor analysis, we compute the core tensor which governs the interaction between factors organizing the original tensor, and then compose the basis to recognize the individual in the online recognition framework. Finally, we recognize the individual using the computation of similarity based on the Euclidean distance, which is more suitable to our method. We verify the superiority of the proposed approach via experiments with real gait sequences.     

基于主运动轮廓线的步态表示与识别

提出了一个基于步态主运动轮廓线构造特征矩阵, 并进行特征表示和分类识别的算法. 该算法首先从步态轮廓线提取三段代表人体主要运动的部分, 基于它们到质心的横向距离构造描述步态图像序列的三个特征矩阵. 然后, 采用主分量分析(Principal component analysis, PCA)方法去除特征矩阵中的冗余数据, 并利用多元判别分析(Multiple discriminant analysis, MDA)将特征矩阵投影到更易于分类的空间. 最后, 在USF步态数据库上计算测试对象的Rank n识别率, 并与其他三个有代表性的算法进行比较. 实验结果显示, 本文算法的平均识别率更高, 抗干扰性更强.     

步态识别中的步态检测与序列预处理

步态检测与序列预处理是步态识别的子课题,在人体检测与分割问题上,分别采用光流法、帧间差分法和背景减除法做对比试验。鉴于各种运动检测算法的有效性和复杂性,最终确定采用背景减除法进行行人的检测与分割。针对室内环境采用直接差分的背景减除方法,而室外环境则采用背景实时更新的背景减除方法。用数学形态学填补二值化图像的空洞;再进行单连通的运动分析,提取人的侧影。为了消除图像尺度对识别的影响,运用形态学操作和图形几何变换实现了图像的标准中心化。本文所采用的步态检测与序列预处理方法对后续的步态识别是有效的。     

Choquet模糊积分特征融合的步态识别

研究一种利用Choquet模糊积分对小波矩特征和人体宽度特征进行融合的步态识别算法。该算法对每个步态序列采用背景减除法提取人的二值化的运动轮廓图像序列,利用人体步态周期图像的小波矩特征和宽度特征对提取出的步态轮廓进行描述,得出的小波矩特征和宽度特征根据重要性作为总体特征输入,运用Choquet模糊积分融合选取SVM分类器进行识别,识别结果与最新的线性加权融合识别方法进行比较,结果表明Choquet模糊积分方法有较好的识别效果。