检索结果-内蒙古大学图书馆

Uniform algebraic-trigonometric spline curves

Journal of Information and Computational Science 2007年第2期4卷 463-474页

作者： Chen, Wenyu Wang, Guozhao Institute of Computer Graphics and Image Processing Department of Mathematics Zhejiang University Hangzhou 310027 China

Based on the space spanned by {1, t, , tn-5, sint, cost, t sin t, t cos t}, (n≥5), this paper presents a new kind of uniform splines. These splines are called uniform algebraic-trigonometric splines, which share most of the properties as those of the B-splines in the polynomial space. Such splines can encompass conical solenoids, involutes of circles and some other transcendent curves. The subdivision scheme of this new kind of curves is given, and it is verified to be convergent. The subdivision scheme is equal to a series of linear subdividing process, which followed the V.D. property and the convexity preserving property of the splines.

关键词： Splines

来源：评论

学校读者我要写书评

暂无评论

Sparse MRF appearance models for fast anatomical structure localisation

Sparse MRF appearance models for fast anatomical structure l...

引用

2007 18th British Machine Vision Conference, BMVC 2007

作者： Donner, René Mičušsík, Branislav Langs, Georg Bischof, Horst Institute for Computer Graphics and Vision Graz University of Technology Austria Pattern Recognition and Image Processing Group Vienna University of Technology Austria GALEN Group Laboratoire de Mathématiques Appliquées Aux Systèmes Ecole Centrale de Paris France

ISBN: (纸本)1901725340

image segmentation methods like active shape models, active appearance models or snakes require an initialisation that guarantees a considerable overlap with the object to be segmented. In this paper we present an approach that localises anatomical structures in a global manner by means of Markov Random Fields (MRF). It does not need initialisation, but finds the most plausible match of the query structure in the image. It provides for precise, reliable and fast detection of the structure and can serve as initialisation for more detailed segmentation steps. Sparse MRF Appearance Models (SAMs) encode a priori information about the geometric configurations of interest points, local features at these points and local features along the edges of adjacent points. This information is used to formulate a Markov Random Field and the mapping of the modeled object (e.g. a sequence of vertebrae) to the query image interest points is performed by the MAX-SUM algorithm. The local image information is captured by novel symmetry-based interest points and local descriptors derived from Gradient Vector Flow. Experimental results are reported for two data-sets showing the applicability to complex medical data.

关键词： image segmentation

来源：评论

学校读者我要写书评

暂无评论

Active segmentation and adaptive tracking using level sets

Active segmentation and adaptive tracking using level sets

引用

2007 18th British Machine Vision Conference, BMVC 2007

作者： Chen, Zezhi Wallace, Andrew M. School of Mathematics and Computer Sciences United Kingdom School of Engineering and Physical Sciences Joint Research Institute in Signal and Image Processing Heriot-Watt University Edinburgh EH14 4AS United Kingdom

ISBN: (纸本)1901725340

We describe algorithms for active segmentation (AS) of the first frame, and subsequent, adaptive object tracking through succeeding frames, in a video sequence. Object boundaries that include different known colours are segmented against complex backgrounds;it is not necessary for the object to be homogeneous. As the object moves, we develop a tracking algorithm that adaptively changes the colour space model (CSM) according to measures of similarity between object and background. We employ a kernel weighted by the normalized Chamfer distance transform, that changes shape according to a level set definition, to correspond to changes in the perceived 2D contour as the object rotates or deforms. This improves target representation and localisation. Experiments conducted on various synthetic and real colour images illustrate the segmentation and tracking capability and versatility of the algorithmin comparison with results using previously publishedmethods.

关键词： Color

来源：评论

学校读者我要写书评

暂无评论

Local Structure Detection with Orientation-invariant Radial Configuration

Local Structure Detection with Orientation-invariant Radial ...

引用

Conference on computer Vision and Pattern Recognition (CVPR)

作者： Lech Szumilas Rene Donner Georg Langs Allan Hanbury Pattern Recognition and Image Processing Group University of Technology Vienna Vienna Austria Institute for Computer Graphics and Vision Graz University of Technology Graz Austria

Local image descriptors have proved themselves as useful tools for many computer vision tasks such as matching points between multiple images of a scene and object recognition. Current descriptors, such as SIFT, are designed to match image features with unique local neighborhoods. However, the interest point detectors used with SIFT often fail to select perceptible local structures in the image, and the SIFT descriptor does not directly encode the local neighborhood shape. In this paper we propose a symmetry based interest point detector and radial local structure descriptor which consistently captures the majority of basic local image structures and provides a geometrical description of the structure boundaries. This approach concentrates on the extraction of shape properties in image patches, which are an intuitive way to represent local appearance for matching and classification. We explore the specificity and sensitivity of this local descriptor in the context of classification of natural patterns. The implications of the performance comparison with standard approaches like SIFT are discussed.

关键词： Detectors Shape computer vision Layout Object recognition

来源：评论

学校读者我要写书评

暂无评论

A comparision of Model-based methods for knee cartilage segmentation

A comparision of Model-based methods for knee cartilage segm...

引用

2nd International Conference on computer Vision Theory and Applications, VISAPP 2007

作者： Cheong, J. Faggian, N. Langs, G. Suter, D. Cicuttini, F. Dept. of Electrical Dept. of Computer Systems Engineering Monash University Australia Clayton School of Information Technology Monash University Australia Institute for Computer Graphics and Vision Graz University of Technology Austria Pattern Recognition and Image Processing Group Vienna University of Technology Austria Dept. of Epidemiology Dept. of Preventive Medicine Monash University Australia

Osteoarthritis is a chronic and crippling disease affecting an increasing number of people each year. With no known cure, it is expected to reach epidemic proportions in the near future. Accurate segmentation of knee cartilage from magnetic resonance imaging (MRI) scans facilitates the measurement of cartilage volume present in a patient's knee, thus enabling medical clinicians to detect the onset of osteoarthritis and also crucially, to study its effects. This paper compares four model-based segmentation methods popular for medical data segmentation, namely Active Shape Models (ASM) (Cootes et al., 1995), Active Appearance Models (AAM) (Cootes et al., 2001), Patch-based Active Appearance Models (PAAM) (Faggian et al., 2006), and Active Feature Models (AFM) (Langs et al., 2006). A comprehensive analysis of how accurately these methods segment human tibial cartilage is presented. The results obtained were benchmarked against the current "gold standard" (cartilage segmented manually by trained clinicians) and indicate that modeling local texture features around each landmark provides the best results for segmenting human tibial cartilage.

关键词： Medical imaging

来源：评论

学校读者我要写书评

暂无评论

On ancient coin classification

On ancient coin classification

引用

8th International Symposium on Virtual Reality, Archaeology, and Intelligent Cultural Heritage, VAST 2007

作者： Zaharieva, M. Huber-Mörk, R. Nölle, M. Kampel, M. TU Vienna Institute for Computer Aided Automation Pattern Recognition and Image Processing Group Favoritenstr. 9/183-2 A-1040 Vienna Austria ARC Seibersdorf Research GmbH Smart Systems Division High Performance Image Processing A-2444 Seibersdorf Austria ARC Seibersdorf Research GmbH Smart Systems Division Quantum Technologies A-2444 Seibersdorf Austria

ISBN: (纸本)9783905674019

Illegal trade and theft of coins appears to be a major part of the illegal antiques market. image based recognition of coins could substantially contribute to fight against it. Central component in the permanent identification and traceability of coins is the underlying classification and identification technology. The first step of a computer aided system is the segmentation of the coin in the image. Next, a feature extraction process measures the coin in order to describe the coin unambiguously. In this paper, we focus on the segmentation task, followed by a comparison of features relevant for coin classification. Results of the algorithms implemented are presented for an image database of ancient coins. © The Eurographics Association 2007.

关键词： image segmentation

来源：评论

学校读者我要写书评

暂无评论

Video Object Tracking Based on a Chamfer Distance Transform

Video Object Tracking Based on a Chamfer Distance Transform

引用

IEEE International Conference on image processing

作者： Zezhi Chen Zsolt L Husz Iain Wallace Andrew M Wallace Joint Research Institute in Signal and Image Processing School of Mathematics and Computer Science Heriot-Watt University Edinburgh UK Joint Research Institute in Signal and Image Processing School of Engineering and Physical Sciences Heriot-Watt University Edinburgh UK

This paper describes the use of variable kernels based on the normalized Chamfer distance transform (NCDT) for mean shift, object tracking in colour video sequences. This replaces the more usual Epanechnikov kernel, improving target representation and localization without increasing the processing time, minimising the distance between successive frame RGB distributions using the Bhattacharya coefficient. The target shape which defines the NCDT is found either by regional segmentation or background-difference imaging, dependent on the nature of the video sequence. The improved performance is demonstrated on a number of colour video sequences.

关键词： Kernel Video sequences image segmentation Histograms Target tracking Robust stability Signal processing image processing Mathematics computer science

来源：评论

学校读者我要写书评

暂无评论

Multistage Lattice Vector Quantization for Hyperspectral image Compression

Multistage Lattice Vector Quantization for Hyperspectral Ima...

引用

Asilomar Conference on Signals, Systems & computers

作者： Ying Liu William A. Pearlman Center for Image Processing Research Electrical Computer and Systems Engineering Department Rensselaer Polytechnic Institute Troy NY USA

Lattice vector quantization (LVQ) offers substantial reduction in computational load and design complexity due to the lattice regular structure [1]. In this paper, we extended the SPIHT [2] coding algorithm with lattice vector quantization to code hyperspectral images. In the proposed algorithm, multistage lattice vector quantization (MLVQ) is used to exploit correlations between image slices, while offering successive refinement with low coding complexity and computation. Different four-dimensional lattices and significance metrics are considered. Their rate-distortion performance is compared with other 2D and 3D wavelet-based image compression algorithms.

关键词： Lattices Vector quantization Hyperspectral imaging image coding Partitioning algorithms Bit rate image processing Design engineering Systems engineering and theory Rate-distortion

来源：评论

学校读者我要写书评

暂无评论

Emulated digital CNN solution for two dimensional compressible flows

Emulated digital CNN solution for two dimensional compressib...

引用

European Conference on Circuit Theory and Design, ECCTD

作者： Sandor Kocsardi Zoltan Nagy Peter Szolgay Department of Image Processing and Neurocomputing University of Pannonia Veszprem Hungary Computer and Automation Research Institute Hungarian Academy of Sciences (ATOMKI) Budapest Hungary

In the area of mechanical, aerospace, chemical and civil engineering the solution of partial differential equations (PDEs) has been one of the most important problems of mathematics for a long time. Inside that one of the most exciting fields is the simulation of fluid flow, which involves for example problems of air, sea and land vehicle motion. In this paper a CNN-UM based solver of 2D inviscid, isothermal, compressible fluids will be presented. Unfortunately the necessity of the coupled multi-layered computational structure with non-linear, space-variant templates does not make it possible to utilize the huge computing power of the analog CNN-UM chips. To improve the performance of our solution an emulated digital CNN-UM has been used.

关键词： Cellular neural networks Analog computers Aerospace engineering Chemical engineering Civil engineering Partial differential equations Mathematics Computational modeling Fluid flow Land vehicles

来源：评论

学校读者我要写书评

暂无评论

AMC-HARQ system baded on RC-LDPC codes in MIMO channels

AMC-HARQ system baded on RC-LDPC codes in MIMO channels

引用

1st International Workshop on Cross Layer Design, IWCLD 2007

作者： Li, Changchun Zhang, Yuling Yuan, Dongfeng Wang, Chengxiang School of Information Science and Engineering Shandong University Jinan Shandong 250100 China School of Computer Science and Technology Ludong University Yantai Shandong 250100 China Joint Research Institute of Signal and Image Processing School of Engineering and Physical Sciences Heriot-Watt University Edinburgh EH14 4AS United Kingdom

ISBN: (纸本)1424412846

In this paper, we propose a cross-layer design framework combining adaptive modulation and coding (AMC) with hybrid automatic repeat request (HARQ) based on rate-compatible low-density parity-check codes (RC-LDPC) in multiple-input multiple-output (MIMO) fading channels with estimation errors. We derive the expressions for the throughput of the system and investigated the effect of channel estimation errors on the system throughput. Numerical results show that the joint design of AMC and ARQ based on RC-LDPC codes can achieve considerable spectral efficiency gain. © 2007 IEEE.

关键词： Fading channels

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：