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Chinese Journal of Mechanical Engineering 2008年第2期21卷 87-92页

作者： CAO Wanpeng BI Wei CHE Rensheng GUO Wenbo YE Dong Department of Automatic Measurement and Control Harbin Institute of Technology Harbin 150001 China China Academy of Machinery Science and Technology Beijing 100044 China Department of Electrical Engineering and Automation Harbin Institute of Technology Harbin 150001 China

A new motion model and estimation algorithm is proposed to compute the general rigid motion object＇s 6-DOF motion parameters and center of rotation based on stereo vision. The object＇s 6-DOF motion model is designed from the rigid object＇s motion character under the two defined reference frames. According to the rigid object＇s motion model and motion dynamics knowledge, the corresponding motion algorithm to compute the 6-DOF motion parameters is worked out. By the rigid object pure rotation motion model and space sphere geometry knowledge, the center of rotation may be calculated after eliminating the translation motion out of the 6-DOF motion. The motion equations are educed based on the motion model and the closed-form solutions are figured out. To heighten the motion estimation algorithm＇s robust, RANSAC algorithm is applied to delete the outliers. Simulation and real experiments are conducted and the experiment results are analyzed. The results prove the motion model＇s correction and algorithm＇s validity.

关键词： motion estimation Center of rotation 6-DOF motion Stereo vision

MOVING OBJECT TRACKING IN DYNAMIC IMAGE SEQUENCE BASED ON estimation OF motion VECTORS OF FEATURE POINTS

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Transactions of Nanjing University of Aeronautics and Astronautics 2009年第4期26卷 295-300页

作者：黎宁周建江张星星南京航空航天大学信息科学与技术学院

An improved estimation of motion vectors of feature points is proposed for tracking moving objects of dynamic image sequence. Feature points are firstly extracted by the improved minimum intensity change （MIC） algorithm. The matching points of these feature points are then determined by adaptive rood pattern searching. Based on the random sample consensus （RANSAC） method, the background motion is finally compensated by the parameters of an affine transform of the background motion. With reasonable morphological filtering, the moving objects are completely extracted from the background, and then tracked accurately. Experimental results show that the improved method is successful on the motion background compensation and offers great promise in tracking moving objects of the dynamic image sequence.

关键词： motion compensation motion estimation feature extraction moving object tracking dynamic image sequence

Simultaneous range and radial velocity estimation with a single narrowband LFM pulse

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Journal of Systems Engineering and Electronics 2012年第3期23卷 372-377页

作者： Chunmao Yeh Jian Yang Xiuming Shan Yingning Peng Department of Electronic Engineering Tsinghua UniversityBeijing 100084E R.China

The mismatch effect induced by the radial motion of a target is analyzed for linear frequency modulated （LFM） signals. Then, a novel integrated processing scheme is proposed to re- solve the delay-Doppler coupling effect in LFM pulse compression. Therefore the range and radial velocity of the target can be si- multaneously estimated with a narrowband LFM pulse. Finally, numerical simulation results demonstrate the effectiveness and good performance of the proposed method.

关键词： delay-Doppler coupling motion estimation linear fre- quency modulated (LFM) pulse extended filtering.

Gradient-Based Approach for Fine Registration of Panorama Images

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Journal of Computer Science & Technology 2004年第5期19卷 691-697页

作者： HuiChen SchoolofInformationScienceandEngineering ShandongUniversityJinan250100P.R.China

This paper studies the application of gradient-based motion detectiontechniques (i.e., optical flow methods) for registration of adjacent images taken using a hand-heldcamera for the purposes of building a panorama. A general 8-parameter model or a more compact3-parameter model is commonly used for transformation estimation. However, both models areapproximations to the real situation when viewpoint position is not absolutely fixed but includes asmall translation, and thus distortion and blurring are sometimes present in the final registrationresults. This paper proposes a new 5-parameter model that shows better result and has less strictrequirement on good choice of unknown initial parameters. An analysis of disparity recovery rangeand its enlargement using Gaussian filter is also given.

关键词： image registration motion estimation optical flow computer vision

Super-resolution reconstruction of astronomical images using time-scale adaptive normalized convolution

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Chinese Journal of Aeronautics 2018年第8期31卷 1752-1763页

作者： Rui GUO Xiaoping SHI Yi ZHU Ting YU Control and Simulation Center Harbin Institute of Technology Harbin 150080 China Tianjin Branch of China Petroleum Pipeline Engineering Company Limited Tianjin 300457 China

In this work, we describe a new multiframe Super-Resolution（SR） framework based on time-scale adaptive Normalized Convolution（NC）, and apply it to astronomical images. The method mainly uses the conceptual basis of NC where each neighborhood of a signal is expressed in terms of the corresponding subspace expanded by the chosen polynomial basis function. Instead of the conventional NC, the introduced spatially adaptive filtering kernel is utilized as the applicability function of shape-adaptive NC, which fits the local image structure information including shape and orientation. This makes it possible to obtain image patches with the same modality,which are collected for polynomial expansion to maximize the signal-to-noise ratio and suppress aliasing artifacts across lines and edges. The robust signal certainty takes the confidence value at each point into account before a local polynomial expansion to minimize the influence of ***, the temporal scale applicability is considered to omit accurate motion estimation since it is easy to result in annoying registration errors in real astronomical applications. Excellent SR reconstruction capability of the time-scale adaptive NC is demonstrated through fundamental experiments on both synthetic images and real astronomical images when compared with other SR reconstruction methods.

关键词： Astronomical image processing motion estimation Normalized Convolution(NC) Polynomial expansion Signal-to-noise ratio Super-Resolution (SR)reconstruction

A Fast Block—Matching Algorithm Using Smooth motion Vector Field Adaptive Search Technique

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Journal of Computer Science & Technology 2003年第1期18卷 14-21页

作者：李波李炜涂亚明 Digital Media Laboratory Department of Computer Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 P.R. China

In many video standards based on inter-frame compression such as H.26x and MPEG, block-matching algorithm has been widely adopted as the method for motion estimation because of its simplicity and effectiveness. Nevertheless, since motion estimation is very complex in computing. Fast algorithm for motion estimation has always been an important and attractive topic in video compression. From the viewpoint of making motion vector field smoother, this paper proposes a new algorithm SMVFAST. On the basis of motion correlation, it predicts the starting point by neighboring motion vectors according to their SADs. Adaptive search modes are usedin its search process through simply classifying motion activity. After discovering the ubiquitous ratio between the SADs of the collocated blocks in the consecutive frames, the paper proposes an effective half-stop criterion that can quickly stop the search process with good enough *** show that SMVFAST obtains almost the same results as the full search at very low computation cost, and outperforms MVFAST and PMVFAST in speed and quality, which are adopted by MPEG-4.

关键词： video encoder video compression motion estimation block matching MPEG H.263

A comprehensive review of significant researches on content based indexing and retrieval of visual information

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Frontiers of Computer Science 2013年第5期7卷 782-799页

作者： R. PRIYA T. N. SHANMUGAM Department of Mathematics Anna University-Chennai Chennai 600 025 India

Developments in multimedia technologies have paved way for the storage of huge collections of video doc- uments on computer systems. It is essential to design tools for content-based access to the documents, so as to allow an efficient exploitation of these collections. Content based anal- ysis provides a flexible and powerful way to access video data when compared with the other traditional video analysis tech- niques. The area of content based video indexing and retrieval （CBVIR）, focusing on automating the indexing, retrieval and management of video, has attracted extensive research in the last decade. CBVIR is a lively area of research with endur- ing acknowledgments from several domains. Herein a vital assessment of contemporary researches associated with the content-based indexing and retrieval of visual information. In this paper, we present an extensive review of significant researches on CBV1R. Concise description of content based video analysis along with the techniques associated with the content based video indexing and retrieval is presented.

关键词： nultimedia information content based video retrieval (CBVR) content based video indexing and retrieval (CBVIR) shot segmentation object segmentation feature extraction indexing motion estimation querying key frame retrieval and indexing.

Adaptive Control of Lower-Limb Exoskeletons for Walking Assistance Based on Inter-Joint Coordination

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Journal of Bionic Engineering 2024年第4期21卷 1775-1787页

作者： Chaoyang Li Lincong Luo Zhi Liu Tianchi Chen Songxiang Liu Ye He Xiaoan Chen Lei Li Wei Tech Ang School of Mechanical Engineering Chongqing UniversityChongqing400044China Rehabilitation Research Institute of Singapore Singapore308232Singapore Department of Orthopedics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore639798Singapore

Unilateral motor impairment can disrupt the coordination between the joints,impeding the patient’s normal *** assist such patients to walk normally and naturally,an adaptive control algorithm based on inter-joint coordination was proposed in this work for lower-limb *** control strategy can generate the reference trajectory of the affected leg in real time based on a motion coordination model between the joints,and adopt an adaptive controller with virtual windows to track the reference *** Short-Term Memory(LSTM)network was also adopted to establish the coordination model between the joints of both lower limbs,which was optimized by preprocessing angle information and adding gait phase *** the adaptive controller,the virtual windows were symmetrically distributed around the reference trajectory,and its width was adjusted according to the gait phase of the auxiliary *** addition,the impedance parameters of the controller were updated online to match the motion capacity of the affected leg based on the spatiotemporal symmetry factors between the bilateral *** LSTM coordination model demonstrated good accuracy and generality in the gait database of seven individuals,with an average root mean square error of 3.5 and 4.1 for the hip and knee joint angle estimation,*** further evaluate the control algorithm,four healthy subjects walked wearing the exoskeleton while additional weights were added around the ankle joint to simulate an asymmetric *** the experimental results,it was shown that the algorithm improved the gait symmetry of the subjects to a normal level while exhibiting great adaptability to different subjects.

关键词： Lower-limb exoskeleton Adaptive control Gait symmetry Inter-joint coordination motion estimation

An improved partial SPIHT with classified weighted rate-distortion optimization for interferential multispectral image compression

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Chinese Optics Letters 2008年第5期6卷 331-333页

作者：王柯俨吴成柯孔繁锵张磊 State Key Laboratory of Integrated Service Networks Xidian University

Based on the property analysis of interferential multispectral images, a novel compression algorithm of partial set partitioning in hierarchical trees （SPIHT） with classified weighted rate-distortion optimization is presented. After wavelet decomposition, partial SPIHT is applied to each zero tree independently by adaptively selecting one of three coding modes according to the probability of the significant coefficients in each bitplane. Meanwhile the interferential multispectral image is partitioned into two kinds of regions in terms of luminous intensity, and the rate-distortion slopes of zero trees are then lifted with classified weights according to their distortion contribution to the constructed spectrum. Finally a global rate- distortion optimization truncation is performed. Compared with the conventional methods, the proposed algorithm not only improves the performance in spatial domain but also reduces the distortion in spectral domain.

关键词： Boolean functions Data compression Electric distortion Image coding Image compression motion estimation Optimization Programming theory Risk assessment Signal distortion Video signal processing Wavelet decomposition Wavelet transforms