基于改进PointNet网络的三维手姿估计方法

针对单幅深度图像三维手姿估计中由于手部复杂结构捕捉困难导致的精度低和鲁棒性较差的问题,提出一种基于改进PointNet网络的三维手姿估计方法。该方法首先采用边界框定位网络预测三维边界框,从而准确裁剪手部区域。然后将手部深度图像表示为点云,模拟手部可见表面,有效地利用深度图像中的三维信息。最后将手部点云数据输入改进的PointNet网络,准确地进行三维手姿估计。改进的PointNet网络通过引入跳跃连接,充分利用不同层次的特征,更好地捕捉手部的复杂结构。在NYU手姿数据集上进行验证,实验结果表明,提出的方法优于现有的大部分方法,并且网络结构简单、易于训练,运行速度快。     

基于HOG算子的手型特征提取算法

手型是动态手势的一个重要特征。已有的动态手势识别方法虽利用了手型信息,但是信息都隐含在数据中。对此提出一种动态手势中手型特征的提取算法。该算法能准确识别出动态手势中的手型特征。通过Kinect获取手部位置数据,计算手势样本的手局部图像的HOG(Histogram of Oriented Gradient)算子,通过统计手势过程中,临近帧的手局部图像的HOG算子的相似性,确定该样本的手型特征所在帧。实验结果显示,其手型特征识别平均正确率达到92.78%。     

基于Kinect的手语识别方法

为实现基于Kinect的手语识别,提出了一种利用有限状态机及动态时间规整(DTW)的动态手语识别方法。首先,利用Kinect技术得到人体深度图像和骨骼特征信息;然后利用手部分割算法得到手部深度图像,再选取识别正确率高的梯度方向直方图(HOG)特征算子来提取手部特征;最后加入有限状态机和DTW算法实现动态手语识别。实验结果表明:该方法能够实现对常用手语单词、句子的识别,识别准确率可达95%。     

基于人体骨骼和深度图像信息的指尖检测方法

针对复杂环境下的指尖检测,从手部图像分割和指尖检测方法两方面进行改进,提出了一种基于人体骨骼和深度图像信息的指尖检测方法。首先采用Kinect获取人体骨骼和深度图像信息,通过人体骨骼信息锁定目标用户,利用锁定用户的手部节点位置从深度图像中提取手部区域图像;然后从手部骨架中搜索骨架端点,提出局部最优查找方法对轮廓凸包计算结果进行优化;最后结合手部轮廓特征找到指尖位置。实验结果表明,该方法具有良好的检测效果,满足实时性要求,能够实现复杂环境下的鲁棒检测。     

融合深度与肤色特征的自适应手部跟踪算法

手部跟踪技术是实现自然人机交互的关键。针对现有跟踪方法易受光照、环境等影响及鲁棒性差的不足,提出一种融合深度与肤色特征的自适应手部跟踪算法。考虑手部运动过程的形变,该算法首先利用深度平滑连续性选取深度阈值以实现跟踪区域的自适应尺度变化,获得手部候选区域。在此基础上建立YCbCr空间肤色归一化直方图,在粒子滤波框架下将跟踪问题转换为贝叶斯估计问题,基于最大后验准则确定手部位置,并通过监测粒子重要性权值的方差解决跟踪失效问题,实现复杂观测环境下的鲁棒跟踪。实验结果表明,该跟踪算法可适应不同复杂环境,鲁棒性良好。     

融合颜色分割与形状特征的交通标志检测

交通标志的颜色特征和形状特征是其最主要的两个特征,为提高检测的准确性和鲁棒性,提出颜色分割和形状特征相结合的方法。利用交通标志的颜色特征,采用基于HSV空间的颜色分割方法 ,获得图像中可能包含交通标志的区域,并提取该区域。根据交通标志的形状特点,利用canny算子获取提取区域的轮廓。然后,采用基于标记的形状检测算法判定所分割区域的形状,利用方向梯度直方图特征结合支持向量机(SVM)方法完成交通标志识别。经实验测试,该方法对图片视点变换、尺度变换以及亮度变换等情况具有很强的鲁棒性。     

基于多视角学习策略的手部姿态估计

手部姿态估计在人机交互、手功能评估、虚拟现实和增强现实等应用中发挥着重要作用, 为此本文提出了一种新的手部姿态估计方法, 以解决手部区域在大多数图像中占比较小和已有单视图关键点检测算法无法应对遮挡情况的问题. 所提方法首先通过引入Bayesian卷积网络的语义分割模型提取手部目标区域, 在此基础上针对手部定位结果, 利用所提基于注意力机制和级联引导策略的新模型以获得较为准确的手部二维关键点检测结果.然后提出了一种利用立体视觉算法计算关键点深度信息的深度网络, 并在深度估计中提供视角自学习的功能. 该方式以三角测量为基础, 利用RANSAC算法对测量结果进行校准. 最后经过多任务学习和重投影训练对手部关键点的3D检测结果进行优化, 最终提取手部关键点的三维姿态信息. 实验结果表明: 相比于已有的一些代表性人手区域检测算法, 本文方法在人手区域检测上的平均检测精度和运算时间上有一定的改善. 此外, 从本文所提姿态估计方法与已有其他方法的平均端点误差(EPE_mean)和PCK曲线下方面积(AUC)这些指标的对比结果来看, 本文方法的关键点检测性能更优, 因而能获得更好的手部姿态估计结果.     

基于Graph Cuts多特征选择的双目图像分割方法

双目图像分割对后续立体目标合成与三维重建等应用至关重要.由于双目图像中包含场景深度信息,因此直接将单目图像分割方法应用于双目图像尚不能得到理想的分割结果.目前,大多数双目图像分割方法将双目图像的深度特征作为颜色特征的额外通道来使用,仅对颜色特征与深度特征做简单整合,未能充分利用图像的深度特征.文中基于多分类Graph Cuts框架,提出了一种交互式双目图像分割方法.该方法将颜色、深度和纹理等特征融合到一个图模型中,以更充分地利用不同特征信息.同时,在Graph Cuts框架中引入了特征空间邻域系统,增强了图像前景区域与背景区域内部像素点之间的关系,提高了分割目标的完整性.实验结果表明,所提方法有效提升了双目图像分割结果的精确度.     

基于BS-HMM和巴式距离的手势识别技术研究

开发一个基于深度图像的手势识别系统,将巴氏距离(Bhattacharyya distance)引入到贝叶斯感知隐马尔科夫模型(BS-HMM)中,称为BDBS-HMM。使用深度摄像机Kinect捕获深度序列图,通过骨架信息对手部位置进行跟踪,识别手部区域,得到手部分割图;从分割图像中提取4D曲面法线方向分布(HON4D)特征和方向梯度直方图(HOG)特征表示运动模式;将每k个连续的特征向量组合成一个序列分布变换所有训练特征向量,使用分布序列来对BDBS-HMM进行训练。该系统在使用MSRGesture3D数据库和自己建立的数据库的情况下,将BDBS-HMM与标准HMM和BS-HMM进行比较,实验结果表明了该系统的优越性。     

图像区域描述算子研究概况

图像区域表示问题是计算机视觉领域广受关注的焦点问题,在过去几年研究者提出了大量的图像区域表示方法,并取得了显著效果。在分析各描述算子采用的技术特点的基础上,按照区域颜色直方图、基于滤波器的描述算子、基于统计的描述算子和基于矩的描述算子的顺序,对现有的图像区域描述算子做一个回顾,并总结分析各描述算子的优点和局限性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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