检索结果-内蒙古大学图书馆

Multi-human tracking from sparse detection responses

IET COMPUTER VISION 2012年第6期6卷 590-602页

作者： Shen, Y. Miao, Z. Beijing Jiaotong Univ Inst Informat Sci Beijing 100044 Peoples R China

In this study, the authors focus on the performance improvements of multi-human tracking from sparse detection responses. Many previous detection-based data association tracking methods used dense detection responses as input, but they did not take into account in the case of sparse detection responses. Dense detection responses are difficult to obtain in complex environments all the time. In order to achieve this goal, they propose a particle-filter-based triple threshold method to build reliable trajectories. Here, they apply topic model to represent human appearance. The appearance of each person can be considered as topic distribution. Then a cost function algorithm is used to associate these trajectories in a time sliding window for final tracking results. The cost function is composed of four parts: appearance cost, motion direction cost, object size cost and distance cost. These four parts are integrated into a unified formula to build this cost function. Finally, they use three challenging datasets to evaluate the performance of the author's approach in the case of dense and sparse detection responses, respectively, and compare with state-of-the-art approaches. The results show that their approach can obtain better tracking performance than that of previous methods in both cases.

关键词： topic model human appearance representation object size cost motion direction cost sparse detection response particle-filter-based triple threshold method time sliding window dense detection response object tracking distance cost detection-based data association tracking appearance cost object detection Optical, image and video signal processing Computer vision and image processing techniques filtering methods in signal processing image representation multihuman tracking particle filtering (numerical methods)

来源：评论

学校读者我要写书评

暂无评论

Robust solution to three-dimensional pose estimation using composite extended Kalman observer and Kalman filter

引用

IET COMPUTER VISION 2012年第2期6卷 140-152页

作者： Taghirad, H. D. Atashzar, S. F. Shahbazi, M. Advanced Robotics and Automated Systems (ARAS) Faculty of Electrical and Computer Engineering K. N. Toosi University of Technology Iran

Three-dimensional (3D) pose estimation of a rigid object by only one camera has a vital role in visual servoing systems, and extended Kalman filter (EKF) is vastly used for this task in an unstructured environment. In this study, the stability of the EKF-based 3D pose estimators is analysed in detail. The most challenging issue of the state-of-the-art EKF-based 3D pose estimators is the possibility of its divergence because of the measurement and model noises. By analysing the stability of conventional EKF-based pose estimators a composite technique is proposed to guarantee the stability of the procedure. In the proposed technique, the non-linear-uncertain estimation problem is decomposed into a non-linear-certain observation in addition to a linear-uncertain estimation problem. The first part is handled using the extended Kalman observer and the second part is accomplished by a simple Kalman filter. Finally, some experimental and simulation results are given in order to verify the robustness of the method and compare the performance of the proposed method in noisy and uncertain environment to the conventional techniques.

关键词： visual servoing Other topics in statistics Kalman filters robust solution Image recognition cameras nonlinear-certain observation nonlinear uncertain estimation problem linear-uncertain estimation problem visual servoing system composite extended Kalman observer pose estimation three-dimensional pose estimation nonlinear filters filtering methods in signal processing Image sensors Computer vision and image processing techniques simple Kalman filter observers unstructured environment EKF-based 3D pose estimator Graphics techniques solid modelling nonlinear estimation camera

来源：评论

学校读者我要写书评

暂无评论

Parameter-dependent mixed H₂/H_∞ filtering for linear parameter-varying systems

引用

IET signal processing 2012年第7期6卷 697-703页

作者： Zhang, H. Shi, Y. Mehr, A. S. Univ Victoria Dept Mech Engn STN CSC Victoria BC V8W 3P6 Canada Univ Saskatchewan Dept Elect & Comp Engn Saskatoon SK S7N 5A9 Canada

In this study, the authors deal with the mixed H-2/H infinity filtering problem for continuous-time systems. The system model is subject to parameter variation and the parameters of the model vary slowly in the polytope. The parameters of the designed filter are dependent on variation, which is measured online. A new design approach is proposed by increasing the flexible dimensions in the solution space. An illustrative example shows the new features of the proposed design approach.

关键词： flexible dimensions system model parameter variation filtering methods in signal processing design approach signal processing theory H∞ filters linear parameter-varying systems continuous-time systems parameter-dependent mixed H2/H∞ filtering continuous time systems H2 filters

来源：评论

学校读者我要写书评

暂无评论

Improved multi-target multi-Bernoulli filter

引用

IET RADAR SONAR AND NAVIGATION 2012年第6期6卷 458-464页

作者： Ouyang, C. Ji, H. Li, C. Xidian Univ Sch Elect Engn Xian 710071 Peoples R China

The cardinality-balanced multi-target multi-Bernoulli (CBMeMBer) filter is a promising algorithm for multi-target tracking. However, there exists a problem that when the legacy tracks cardinality is big enough, the effect of measurement innovation will be negligible, even if the measurement is close to the target state prediction. Such a problem is shown analytically in this study, and then an improved MeMBer filter has been proposed, which balances the posterior cardinality by modifying the legacy rather than the measurement-updated tracks parameters. The sequential Monte Carlo (SMC) implementation of the proposed algorithm is developed and its performance has been verified by simulation experiments.

关键词： legacy modification cardinality-balanced multitarget multi-Bernoulli filter sequential Monte Carlo implementation filtering methods in signal processing improved MeMBer filter posterior cardinality target tracking Monte Carlo methods filtering theory signal processing theory SMC target state prediction multitarget tracking

来源：评论

学校读者我要写书评

暂无评论

Hardware-software co-design architecture for Joint Photo Expert Graphic XR encoder

引用

IET IMAGE processing 2012年第9期6卷 1284-1292页

作者： Tseng, C. -F. Lai, Y. -T. Natl Cheng Kung Univ Dept Elect Engn Tainan 701 Taiwan

In recent years, because of to the fast growing of internet and digital multi-media, new image compression algorithms are needed to reduce the transferring bandwidth and the decay of image quality. Joint Photo Expert Graphic (JPEG) extended range (XR) is a new standard for still image compression. Compared to previous standards, it provides better image quality and plentiful pixel format. However, the better image quality often comes with the higher computation complexity. In this study, the authors propose a hardware-software co-design architecture for JPEG XR encoder. For photo overlap transform (POT), and photo core transform (PCT), the complicated parts of JPEG XR, the authors propose new algorithms which eliminate data dependency in the basic filters of POT and PCT so that operations can be executed in parallel. The processing rate of the new algorithms is much faster. The authors also demonstrate a basic filter with multiple functions, which can be time-shared by POT and PCT;the hardware cost can be therefore reduced. Moreover, a memory saving scheme is proposed. Therefore the proposed architecture is suitable for stand-alone application-specific integrated circuit (ASIC). In our co-design, POT and PCT are implemented in hardware and then mapped to field programmable gate array (FPGA), whereas the other procedures of JPEG XR such as quantisation are executed by ARM926-EJ processor. The overall performance of our hardware architecture is 50 fps for 4:4:4 HDTV format at 166 MHz.

关键词： frequency 166 MHz image quality ASIC filtering methods in signal processing photo core transform ARM926-EJ processor data compression hardware-software codesign digital multimedia image compression algorithm JPEG XR encoder field programmable gate arrays Hardware-software codesign Internet Electronic engineering computing FPGA joint photo expert graphic XR encoder Computer vision and image processing techniques computer architecture Image and video coding still image compression application specific integrated circuits image coding hardware architecture photo overlap transform data dependency Integral transforms POT quantisation (signal) Logic circuits Computer architecture computation complexity quantisation JPEG extended range stand-alone application-specific integrated circuit PCT Logic and switching circuits memory saving scheme HDTV format filtering theory filter bandwidth transfer hardware-software co-design architecture field programmable gate array Digital circuit design, modelling and testing transforms

来源：评论

学校读者我要写书评

暂无评论

Nonlinear minimum variance estimation for state-dependent discrete-time systems

引用

IET signal processing 2012年第4期6卷 379-391页

作者： Grimble, M. Univ Strathclyde Ind Control Ctr Dept Elect & Elect Engn Glasgow G1 1XW Lanark Scotland

A state-dependent model and nonlinear operator-based approach to estimation and filtering is introduced for discrete-time multi-channel systems including time delays. The problem involves a signal entering a communications channel involving nonlinearities and transport delay elements. The measurements are assumed to be corrupted by a coloured noise signal which is correlated with the signal to be estimated. The communications channel may include either static or dynamic nonlinearities represented by a general nonlinear operator and/or a state-dependent model form. The theoretical solution does not involve empirical assumptions or linearisation approximations. The resulting algorithm is relatively simple to derive and to implement and the solution has an estimator block structure that can be justified intuitively.

关键词： communications channel state-dependent discrete-time systems telecommunication channels static nonlinearities correlation methods coloured noise signal general nonlinear operator nonlinear operator-based approach discrete-time multichannel systems nonlinear minimum variance estimation linearisation techniques delays filtering methods in signal processing approximation theory time delays discrete time systems dynamic nonlinearities Interpolation and function approximation (numerical analysis) linearisation approximations estimator block structure filtering theory nonlinearities delay elements transport delay elements

来源：评论

学校读者我要写书评

暂无评论

Cardiac disorder classification by heart sound signals using murmur likelihood and hidden Markov model state likelihood

引用

IET signal processing 2012年第4期6卷 326-334页

作者： Kwak, C. Kwon, O. -W. Chungbuk Natl Univ Dept Control & Robot Engn Cheongju South Korea

This study proposes a new algorithm for cardiac disorder classification by heart sound signals. The algorithm consists of three steps: segmentation, likelihood computation and classification. In the segmentation step, the authors convert heart sound signals into mel-frequency cepstral coefficient features and then partition input signals into S1/S2 intervals by using a hidden Markov model (HMM). In the likelihood computation step, using only a period of heart sound signals, the authors compute the HMM 'state' likelihood and murmur likelihood. The 'state' likelihood is computed for each state of HMM-based cardiac disorder models, and the murmur likelihood is obtained by probabilistically modelling the energies of band-pass filtered signals for the heart pulse and murmur classes. In the classification step, the authors decided the final cardiac disorder by combining the state likelihood and the murmur likelihood by using a support vector machine. In computer experiments, the authors show that the proposed algorithm greatly improve classification accuracy by effectively reducing the classification errors for the cardiac disorder categories where the temporal murmur position plays an important role in detecting disorders.

关键词： Probability theory, stochastic processes, and statistics Biology and medical computing hidden Markov model state likelihood probabilistic modelling murmur class disorder detection murmur likelihood Bioelectric signals S1/S2 interval Digital signal processing probability cepstral analysis diseases heart pulse cardiac disorder classification mel-frequency cepstral coefficient band-pass filtered signal Knowledge engineering techniques HMM-based cardiac disorder model likelihood computation Markov processes support vector machine filtering methods in signal processing patient diagnosis heart sound signal segmentation Patient diagnostic methods and instrumentation Electrodiagnostics and other electrical measurement techniques medical signal processing hidden Markov models band-pass filters cardiology HMM state likelihood support vector machines signal classification

来源：评论

学校读者我要写书评

暂无评论

Robust equalisation for inter symbol interference communication channels

引用

IET signal processing 2012年第2期6卷 73-78页

作者： Zhang, H. Shi, Y. Mehr, A. Saadat Univ Victoria Dept Mech Engn STN CSC Victoria BC V8W 3P6 Canada Univ Saskatchewan Dept Elect & Comp Engn Saskatoon SK S7N 5A9 Canada

The problem of equalisation for communication channels with inter symbol interference (ISI) is investigated in this study. One practical yet challenging constraint for a channel with high transmission rate is incorporated into the modelling of the equalisation system: the communication channel is subject to uncertainties, which are assumed to be within a polytope with finite vertices. By using the augmentation method, the filtering error system of the equalisation problem is also characterised as a system with polytopic uncertainties. Sufficient conditions on the stability and the H-infinity performance for the filtering error system are obtained. A design method for the equaliser is proposed such that the filtering error system can achieve minimal H-infinity performance index even with the channel uncertainties. Two illustrative design examples demonstrate the design procedure and the effectiveness of the proposed method.

关键词： intersymbol interference Electromagnetic compatibility and interference stability filtering methods in signal processing ISI channel uncertainties finite vertices H∞ performance augmentation method polytopic uncertainty robust equalisation Communication channel equalisation and identification channel estimation filtering theory transmission rate equalisers intersymbol interference communication channel filtering error system

来源：评论

学校读者我要写书评

暂无评论

Fast and robust skew estimation in document images through bilinear filtering model

引用

IET IMAGE processing 2012年第6期6卷 761-769页

作者： Guan, Y-P. Shanghai Univ Sch Commun & Informat Engn Key Lab Adv Displays & Syst Applicat Minist Educ Shanghai 200072 Peoples R China

Skew estimation of scanned document is important for document analysis and recognition. Owing to the complexity inherent in the document, some methods only process the documents with a small skew angle or specified content, layout and have high computational cost. A fast and robust skew estimation method is proposed based on a bilinear filtering model, which is used to detect edges existing in the document. Some foreground areas in the document have been extracted without considering document layouts or contents. The proposed approach enhances the structure of the document and reduces the effects of the noises in the document. It combines filtering operators into a single approach, so noise filtering which is an unavoidable pre-processing in the previous skew detection methods has been overcome. A dominant angle has been estimated based on the detected edges. According to the estimated dominant angle, a skew angle can be determined efficiently without confining the search space or making assumptions including skew angle range and layout of the document in advance. The proposal greatly reduces the computational time and works in an unsupervised style. Comparative tests with the state-of-the-art skew estimation methods indicate the superior performance of the developed approach.

关键词： document image recognition edge detection filtering theory document analysis Image recognition skew detection methods image denoising robust skew estimation method Computer vision and image processing techniques noise filtering approach feature extraction Document processing techniques filtering methods in signal processing dominant angle estimation document image processing small skew angle bilinear filtering model noise effect reduction

来源：评论

学校读者我要写书评

暂无评论

Integrated navigation for an autonomous underwater vehicle carrying synthetic aperture sonar

引用

IET RADAR SONAR AND NAVIGATION 2012年第9期6卷 905-912页

作者： Xu, W. Sun, F. Li, J. Zhejiang Univ Dept Informat Sci & Elect Engn Hangzhou 310027 Peoples R China

As the autonomous underwater vehicle (AUV) becomes more popular in various ocean applications, its navigation technique has attracted great attention since it is often crucial that the vehicle position be known precisely. Selection of a practical navigation scheme is a tradeoff between performance, space/power budget and cost. In this study, a low-cost, small-size navigation system for an AUV carrying synthetic aperture sonar (SAS) is presented. An integrated navigation method is also developed based on the extended Kalman filter, in which two novel processes, track-based compass calibration and adaptive beamforming-based SAS micro-navigation, are incorporated. For compass calibration, the heading bias caused by hard iron interferences is estimated through a surface calibration run;for displaced phase centre antenna-based micro-navigation, sway estimation is done by applying adaptive beamforming to the overlapped phase centre array. A number of AUV field tests were implemented and the results demonstrate that a relative navigation error of as low as 0.23% of the travelling distance in circular runs can be achieved using the developed approach.

关键词： autonomous underwater vehicle calibration AUV field tests nonlinear filters overlapped phase centre array Oceanographic and hydrological techniques and equipment surface calibration hard iron interferences adaptive beamforming-based SAS micronavigation AUV Sonar and acoustic radar adaptive beamforming space-power budget autonomous underwater vehicles filtering methods in signal processing SAS Kalman filters extended Kalman filter displaced phase centre antenna-based micronavigation low-cost small-size navigation system array signal processing track-based compass calibration synthetic aperture sonar integrated navigation method Measurement standards and calibration antennas

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：