GCA-Net: Gait contour automatic segmentation model for video gait recognition

Multimedia Tools and Applications - Gait recognition from videos is a very important task for surveillance video analysis. Although a number of studies have explored gait recognition models, they...     

Gait recognition using linear time normalization

We present a novel system for gait recognition. Identity recognition and verification are based on the matching of linearly time-normalized gait walking cycles. A novel feature extraction process is also proposed for the transformation of human silhouettes into low-dimensional feature vectors consisting of average pixel distances from the center of the silhouette. By using the best-performing of the proposed methodologies, improvements of 8-20% in recognition and verification performance are seen in comparison to other known methodologies on the “Gait Challenge” database.     

一种基于联合轮廓特征矢量的目标识别方法

针对基于形状特征进行目标识别的方法存在的不足,提出一种联合轮廓不变矩特征和轮廓几何特征的识别方法;针对不同的待识别目标,采集足够数量的训练样本,统计每一个轮廓特征的均值、标准差和变异系数;并据此对这些轮廓特征进行动态筛选和加权,建立起待识别目标的联合轮廓特征矢量模型.在线识别时,提取场景目标的联合轮廓特征矢量,对其进行...     

Face recognition using difference vector plus KPCA

In this paper, a novel approach for face recognition based on the difference vector plus kernel PCA is proposed. Difference vector is the difference between the original image and the common vector which is obtained by the images processed by the Gram-Schmidt orthogonalization and represents the common invariant properties of the class. The optimal feature vectors are obtained by KPCA procedure for the difference vectors. Recognition result is derived from finding the minimum distance between the test difference feature vectors and the training difference feature vectors. To test and evaluate the proposed approach performance, a series of experiments are performed on four face databases: ORL, Yale, FERET and AR face databases and the experimental results show that the proposed method is encouraging.     

Human motion recognition using support vector machines

We propose a motion recognition strategy that represents each videoclip by a set of filtered images, each of which corresponds to a frame. Using a filtered-image classifier based on support vector machines, we classify a videoclip by applying majority voting over the predicted labels of its filtered images and, for online classification, we identify the most likely type of action at any moment by applying majority voting over the predicted labels of the filtered images within a sliding window. We also define a classification confidence and the associated threshold in both cases, which enable us to identify the existence of an unknown type of motion and, together with the proposed recognition strategy, make it possible to build a real-time motion recognition system that cannot only make classifications in real-time, but also learn new types of motions and recognize them in the future. The proposed strategy is demonstrated on real datasets.     

Gait recognition for person re-identification

The Journal of Supercomputing - Person re-identification across multiple cameras is an essential task in computer vision applications, particularly tracking the same person in different scenes....     

Extracting eyebrow contour and chin contour for face recognition

This paper proposes a novel method for extraction of eyebrow contour and chin contour. We first segment rough eyebrow regions using spatial constrained sub-area K-means clustering. Then eyebrow contours are extracted by Snake method with effective image force. For chin contour extraction, we first estimate several possible chin locations which are used to build a number of curves as chin contour candidates. Based on the chin like edges extracted by proposed chin edge detector, the curve with the largest likeliness to be the actual chin contour is selected. Finally, the credible extracted eyebrow contour and the estimated chin contours are used as geometric features for face recognition. Experimental results show that the proposed algorithms can extract eyebrow contours and chin contours with good accuracy and the extracted features are effective for improving face recognition rates.     

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。     

基于混合不变矩的步态识别

基于步态的身份识别是近几年出现的一种新的生物识别技术.将Zernike矩应用到步态识别中,同时利用小波矩的局部辨析能力,将两种矩结合起来作为识别特征,从而提出一种基于混合不变矩的步态识别方法.为了减少特征向量维数的增加带来的计算复杂度,采用一种改进的BP神经网络用于识别,在保证分类效果的基础上减小计算复杂度.实验结果表明,基于混合不变矩的步态识别方法在识别率上优于基于单一不变矩的方法.     

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.     

基于改进时空步态图的步态识别

基于图像步态识别因缺乏有效动态、时序特征,导致跨视角识别时准确率较低,而基于模型步态识别特征维度不足,容易造成步态识别平均准确率不高。故提出一种改进时空步态图(Improved Chrono-Gait Image,ICGI)及特征融合策略的解决方法,将时序信息与人体下肢关节间角度的规律变化相结合,突出步态运动时下肢的周期性变化。在引入时序信息的基础上,融合下肢关节点间动态特征,建立一个更加丰富、有效的特征集。结合最近邻算法(KNN)建立步态识别模型,在CASIA-B数据集上进行对比实验,证实所提方法能有效提高复杂环境下步态识别精度。     

基于角度统计特征的步态识别

提取角度统计特征,为步态识别提出了一种新途径.用统计的方法,等角度间隔地计算归一化步态轮廓图像各像素点至质心距离的均值与方差,并用其构造步态识别的特征向量.与提取步态轮廓图像边界特征的方法相比,该方法具有算法简单、运算速度快、无需建立复杂的数学模型等优点.以Matlab7.5为平台,以中科院自动化研究所提供的CASIA数据库为样本进行了大量实验,实验结果表明:该步态识别方法具有较好的识别性能.     

Speaker recognition using pyramid match kernel based support vector machines

Gaussian mixture model (GMM) based approaches have been commonly used for speaker recognition tasks. Methods for estimation of parameters of GMMs include the expectation-maximization method which is a non-discriminative learning based method. Discriminative classifier based approaches to speaker recognition include support vector machine (SVM) based classifiers using dynamic kernels such as generalized linear discriminant sequence kernel, probabilistic sequence kernel, GMM supervector kernel, GMM-UBM mean interval kernel (GUMI) and intermediate matching kernel. Recently, the pyramid match kernel (PMK) using grids in the feature space as histogram bins and vocabulary-guided PMK (VGPMK) using clusters in the feature space as histogram bins have been proposed for recognition of objects in an image represented as a set of local feature vectors. In PMK, a set of feature vectors is mapped onto a multi-resolution histogram pyramid. The kernel is computed between a pair of examples by comparing the pyramids using a weighted histogram intersection function at each level of pyramid. We propose to use the PMK-based SVM classifier for speaker identification and verification from the speech signal of an utterance represented as a set of local feature vectors. The main issue in building the PMK-based SVM classifier is construction of a pyramid of histograms. We first propose to form hard clusters, using k-means clustering method, with increasing number of clusters at different levels of pyramid to design the codebook-based PMK (CBPMK). Then we propose the GMM-based PMK (GMMPMK) that uses soft clustering. We compare the performance of the GMM-based approaches, and the PMK and other dynamic kernel SVM-based approaches to speaker identification and verification. The 2002 and 2003 NIST speaker recognition corpora are used in evaluation of different approaches to speaker identification and verification. Results of our studies show that the dynamic kernel SVM-based approaches give a significantly better performance than the state-of-the-art GMM-based approaches. For speaker recognition task, the GMMPMK-based SVM gives a performance that is better than that of SVMs using many other dynamic kernels and comparable to that of SVMs using state-of-the-art dynamic kernel, GUMI kernel. The storage requirements of the GMMPMK-based SVMs are less than that of SVMs using any other dynamic kernel.     

Online learning method using support vector machine for surface-electromyogram recognition

Research surface electromyogram (s-EMG) signal recognition using neural networks is a method which identifies the relation between s-EMG patterns. However, it is not sufficiently satisfying for the user because s-EMG signals change according to muscle wasting or to changes in the electrode position, etc. A support vector machine (SVM) is one of the most powerful tools for solving classification problems, but it does not have an online learning technique. In this article, we propose an online learning method using SVM with a pairwise coupling technique for s-EMG recognition. We compared its performance with the original SVM and a neural network. Simulation results showed that our proposed method is better than the original SVM. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

SketchFormer: transformer-based approach for sketch recognition using vector images

Multimedia Tools and Applications - Sketches have been employed since the ancient era of cave paintings for simple illustrations to represent real-world entities and communication. The abstract...     

Chaincode contour processing for handwritten word recognition

Contour representations of binary images of handwritten words afford considerable reduction in storage requirements while providing lossless representation. On the other hand, the one-dimensional nature of contours presents interesting challenges for processing images for handwritten word recognition. Our experiments indicate that significant gains are to be realized in both speed and recognition accuracy by using a contour representation in handwriting applications