Implementation of AVS Jizhun decoder with HW/SW partitioning on a coarse-grained reconfigurable multimedia system

In this paper,a TPP(Task-based Parallelization and Pipelining)scheme is proposed to implement AVS(Audio Video coding Standard)video decoding algorithm on REMUS(REconfigurable MUltimedia System),which is a coarse-grained reconfigurable multimedia system.An AVS decoder has been implemented with the consideration of HW/SW optimized partitioning.Several parallel techniques,such as MB(Macro-Block)-based parallel and block-based parallel techniques,and several pipeline techniques,such as MB level pipeline and block level pipeline techniques are adopted by hardware implementation,for performance improvement of the AVS decoder.Also,most computation-intensive tasks in AVS video standards,such as MC(Motion Compensation),IP(Intra Prediction),IDCT(Inverse Discrete Cosine Transform),REC(REConstruct)and DF(Deblocking Filter),are performed in the two RPUs(Reconfigurable Processing Units),which are the major computing engines of REMUS.Owing to the proposed scheme,the decoder introduced here can support AVS JP(Jizhun Profile)1920×1088@39fps streams when exploiting a 200 MHz working frequency.     

Implementation of multi-standard video decoder on a heterogeneous coarse-grained reconfigurable processor

This paper proposes a task-based hybrid parallel and hybrid pipeline(THPHP)scheme to implement multi-standard video algorithms,including MPEG-2,H.264,and audio video coding standard(AVS),on a heterogeneous coarse-grained reconfigurable processor,called the reconfigurable multimedia system(REMUS).The proposed schemes greatly improve decoding performance and satisfy the real-time requirements of various high-definition(HD)video decoding standards.In THPHP,we propose both a task-based hybrid parallel scheme,in which macro-block(MB)-level,block-level,and sub-block-level decoding tasks are parallelized to improve data processing throughput,and a hybrid pipeline scheme,in which slice-level,MB-level,block-level and sub-block-level computations are pipelined to improve efficiency.Computation-intensive tasks,such as motion compensation,intra prediction,inverse discrete cosine transform,reconstruction,and deblocking filter,are implemented on two reconfigurable processing units,which are the core computing engines of REMUS.Thanks to the proposed schemes,the implementations can achieve H.264 high profile(HP)1920×1080@30 fps streams,AVS Jizhun profile(JP)1920×1080@39 fps streams,and MPEG-2 main profile(MP)1920×1080@41 fps streams when working at 200 MHz frequency.Compared with XPP-III(a commercial reconfigurable processor),when implementing H.264 HD decoding,the performance and energy efficiency on REMUS are improved by1.81×and 14.3×,respectively.     

Variational PCA fusion for resolution Pan-sharpening very high imagery

The Pan-sharpening approach based on principle component analysis （PCA） is affected by severe spectral distortion. To address this problem, a new pan-sharpening model based on PCA and variational technique is proposed to construct the substitute image of the first principal component （PC1）. The energy functional consists of three terms. The first term injects PC1 with the geometric structure of the panchromatic （Pan） image. The second term preserves the spectral pattern of the multi-spectral image in the merged result. And the third term guarantees the smoothness of the functional optimization solution. The fusion result is given by the minimum of the energy functional, which is computed with the gradient descend flow. The experiments on QuickBird and IKONOS datasets validate the effectiveness of the proposed model. Compared with the state- of-the-art pan-sharpening approaches, this model exhibits a better trade-off between improving spatial quality and preserving spectral signature of the MS image.     

Remote charge scattering： a full Coulomb interaction approach and its impact on silicon nMOS FinFETs with HfO2 gate dielectric

Remote charge scattering(RCS)has become a serious obstacle inhabiting the performance of ultrathin gate oxide MOSFETs.In this paper,we evaluate the impact of RCS by treating the real-space full Coulomb interaction between remote charges and inversion carriers.A new approach that can be simply incorporated in ensemble Monte Carlo(EMC)based simulations without any variation of the standard EMC simulator is developed.The charge-carrier(c-c)interaction model is based on a particle-mesh(PM)calculation method which resolves both the long-range and short-range Coulomb interactions by solving Poisson’s equation on a refined mesh.The validity of our approach is verified by three-dimensional(3-D)resistor simulations,from which the obtained doping dependence of the low-field mobility agrees well with experimental results.The proposed approach is then used to study the impact of RCS on the drive current and carrier transport properties in the channel of a 20 nm silicon(Si)nMOS FinFET with HfO2gate stack.We find that the influence of RCS is strongly localized in the vicinity of the remote charges and exhibits a granular nature,indicating the necessity to consider the full Coulomb interaction in RCS.     

基于矩形特征和改进Adaboost的手势检测

为了实时、精确地从视频流中检测和识别出特定手势,提出一种矩形特征描述手势,给出快速计算方法和手势类可分离性的评价方法。为了避免分类器的过度训练问题,提出一种基于此方法的改进的Adaboost算法。实验结果表明,矩形特征能够产生可靠的检测器,对手势的姿态变化较敏感。在摄像头实时捕获视频中,其检测手势实时性较好,对复杂背景和噪声有较强的适应能力,当手势旋转角度小时,正确检测率可以达到95%以上。     

Gesture Recognition Summarization

Gesture recognition is an important research in the field of human-computer interaction. Hand Gestures are strong variable and flexible, so the gesture recognition has always been an important challenge for the researchers. In this paper, we first outlined the development of gestures recognition, and different classification of gestures based on different purposes. Then we respectively introduced common methods used in the process of gesture segmentation, feature extraction and recognition. Finally, the gesture recognition was summarized and the studying prospects were given.     

气动机器人多指灵巧手——ZJUT Hand

总结了现有灵巧手的缺点,例如结构复杂、难以控制等,并在此基础上提出了一种新型的气动驱动多指灵巧手,命名为ZJUT Hand.基于一种新型的气动柔性驱动器FPA,设计了气动刚柔性弯曲关节及侧摆关节;在此基础上给出了一种4自由度气动拟人手指;为了获得较高的模块化集成度,将5个完全相同的手指装配在拟人手掌上,构成具有5个手指、20个自由度的ZJUT Hand的本体结构;采用仿生学优化方法确定ZJUT Hand的结构参数,并对其本体结构进行了抓持仿真实验.仿真结果表明:ZJUT Hand能够对圆柱、长条形、球形等典型形状的物体实现抓持,并能够模拟人手实现对捏、夹持、勾拉等复杂拟人手形.详细设计了ZJUT Hand的力/位传感系统.完成了ZJUT Hand的抓取实验,结果表明:ZJUT Hand能够对典型形状目标物体实现稳定抓取.最后,简单总结了ZJUT Hand的特色之处.     

基于细径McKibben型气动人工肌肉的仿生手研发

以细径McKibben型气动人工肌肉作为执行器,研发了一种质量轻且具有良好柔顺性、灵巧性的仿生机械手.分别以直径为1.3mm和2mm的细径McKibben型人工肌肉模拟人手的内在肌和外在肌,以人手骨骼、关节、肌肉的生理构造为设计准则,设计并制作仿生手样机.该样机由35根人工肌肉驱动,与人手大小相仿,质量小于0.5 kg.通过实验,对该仿生手的运动性能、目标抓握能力和鲁棒性进行验证,该仿生手可以完成与人手相近的动作.     

基于改进射线矢量法的手部轮廓与手势实时跟踪方法

目前,在视频分析和处理过程中,运动物体的实时检测和与轮廓跟踪作为计算机视觉分析识别的基础,已变得越来越重要了.改进了传统的射线矢量法表示物体形状的方法,并结合拆分法和聚合法对单帧图像进行分割,以得到完整而准确的手部曲线,在相邻帧之间采用了Kalman滤波器估计帧间手部运动的轨迹来实现跟踪过程.该方法很好地克服了传统射线矢量法所无法表示的形状的缺陷,能够准确地跟踪手部的运动以及各种手势.     

基于肤色动态手势区域的标定

针对视频序列中的运动手势,提出一种基于肤色和运动特征的快速标定方法。首先采用帧间差分法提取出运动手势目标;在YCbCr色彩空间中,利用肤色的Cb和Cr分量的高斯分布特性,检测出运动手势目标的肤色区域;经过阈值分割得到手势二值图,利用矩形框将手势区域标定出来。并在实验中证明该方法的有效性。     

基于MJPG-streamer的嵌入式远程视频监控系统

针对远程实验操作中实验动态信息可视化及实时性问题,利用ARM处理器和USB摄像头设计一个基于MJPG-streamer的嵌入式远程视频监控系统.该系统使用基于硬件压缩的USB摄像头进行视频信息采集,搭建MJPG-streamer流媒体服务器来完成视频数据的采集和传输.测试结果表明,该方案在帧率10 fps、分辨率640×480情况下,能实现流畅清晰的视频传输,且平均占用带宽约200 Kb/s,能满足远程实验的需求.     

基于颜色概率模型的实时手势跟踪算法

本文提出了一种改进的CAMSHIFT算法,实现了对动态手势的实时跟踪。将图像序列通过一个肤色概率查找表转换为肤色概率分布图,结合运动信息和肤色概率分布,初始化一个搜索窗的大小和位置,然后对肤色概率分布图进行迭代运算,定位出手势的位置和大小,根据计算肤色概率分布图中手势区域的2阶矩,最终确定感兴趣区域的长度和宽度
。实验表明,本文提出的算法能实时处理视频图像,避免了错误跟踪,而且跟踪准确精细。     

基于嵌入式Linux的农业远程监测系统

针对现有农业远程监测系统成本高、实时性和扩展性差等问题,结合嵌入式技术和Web技术,设计一种由Zc0301摄像头和S3c2440组成的田间视频采集服务器。监测端网内测试结果表明,构建的嵌入视频服务器网络数据包传输速度为1.858 Mb/s,视频传输帧速可达 20 f/s,能满足远程视频监测需求。     

Tele-Graffiti: A Camera-Projector Based Remote Sketching System with Hand-Based User Interface and Automatic Session Summarization

One way to build a remote sketching system is to use a video camera to image what each user draws at their site, transmit the video to the other sites, and display it there using an LCD projector. Such camera-projector based remote sketching systems date back to Paul Wellner's (largely unimplemented) Xerox Double DigitalDesk. To make such a system usable, however, the users have to be able to move the paper on which they are drawing, they have to be able to interact with the system using a convenient interface, and sketching sessions must be stored in a compact format so that they can be replayed later. We have recently developed Tele-Graffiti, a remote sketching system with the following three features: (1) real-time paper tracking to allow the users to move their paper during system operation, (2) a hand based user interface, and (3) automatic session summarization and playback. In this paper, we describe the design, implementation, and performance of Tele-Graffiti.Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1023084706295     

基于自适应阈值的动态手势分割和识别

对手势视频流进行了帧分离,通过对人体肤色的检测来分割手势,识别过程采取了自适应阈值二值化方法进行预处理,特征提取兼顾了手势本身的形状特征和整个手势序列的运动轨迹特征。实验结果证明获得了较高的识别率,此方法是可行的。     

Hand tracking in a natural conversational environment by the interacting multiple model and probabilistic data association (IMM-PDA) algorithm

Traditional image based hand tracking algorithms use a single model Kalman filter to estimate and predict the hand state (position, velocity, and acceleration) and do not consider multiple measurements with noise and false alarms. However, these approaches may fail in the case of large maneuvers and/or a clutter measurement environment. In this paper, we apply the interacting multiple model (IMM) to catch hand maneuvers and the probabilistic data association (PDA) method to process noisy measurements and false alarms. A theoretical framework of image based hand tracking by the IMM-PDA algorithm is set up. Experiment results from several long video segments show that the IMM-PDA algorithm gives a superior performance compared to single model based Kalman filters.     

Performance Evaluation of Antenna Receive Diversity in SlMO-OFDM System over Rayleigh Fading Channel

This paper represents a comparative performance evaluation of different diversity combining techniques for a SIMO-OFDM （single-input-multiple-output orthogonal frequency division multiplexing） system over Rayleigh fading channel. OFDM is a key technique for achieving high data rates and spectral efficiency requirements for wireless communication systems. But in scattering environment, the system performances are severely degraded by the effects of multipath fading and inter-symbol interference. In wireless communication systems, antenna diversity is an important technique to combat multipath fading in order to improve the system performance and increase the channel capacity. In this paper, the performance of different diversity combining techniques-SC （selection combining）, EGC （equal gain combining） and MRC （maximal ratio combining） has been analyzed and compared in terms of SNR （signal to noise ratio） and BER （bit error rate） probability. The simulation results show that the maximal ratio combining technique provides maximum performance improvement relative to all other combining schemes by maximizing the SNR of SIMO-OFDM system at the combiner output. The analytic expressions of error probability and effective bit energy to noise ratio correlated with BPSK （binary phase shift keying） modulation have been derived and formulated for N-branch SC, EGC and MRC schemes. The BER characteristics for all three combining techniques are simulated in MATLAB （matrix laboratory） tool box for varying bit energy to noise ratio. Our results also derives that SNR can be improved if the number of receiving antenna is increased, which in turn reduces BER over a Rayleigh fading channel.     

基于CamShift和Kalman滤波混合的视频手势跟踪算法*

提出了一种基于CamShift和Kalman滤波混合的跟踪算法,实现了对视频图像中动态手势的跟踪。在跟踪过程中,CamShift利用手势的颜色直方图模型,将图像序列通过一个肤色概率查找表转换为肤色概率分布图,结合运动信息和肤色概率分布,初始化一个搜索窗的大小和位置,并根据上一帧跟踪的结果自适应调整搜索窗口的位置和大小,从而定位出当前图像中手势的中心位置。在CamShift算法基础上利用Kalman滤波对搜索窗口进行运动预测。实验表明,该算法快速准确可靠,并且较好地处理了跟踪过程中大面积肤色干扰问题,对复杂