检索结果-内蒙古大学图书馆

conference on Sensor Fusion - Architectures, Algorithms, and Applications v

作者： Li, J Sheng, YL Sévigny, T valin, P Univ Laval COPL Image Sci Grp St Foy PQ G1K 7P4 Canada

ISBN: (纸本)0819440809

Many automatic target recognition, detection, and identification problems usually suffer from lack of adequate resolution of the image data, especially among infrared imaging systems. A number of superresolution reconstruction algorithms have been proposed. The challenge is how to recapture additional high-frequency information from adjacent frames in an image sequence that contains slightly different, but unique, information. In addition, real-world infrared sequence images are noisy with low contrast, and low spatial resolution. Since broad-banded noise mainly affects high-frequency information to be recaptured, the challenge is how to avoid smoothing out the high-frequency data by the regularization are not smoothed out. This paper presents a new superresolution reconstruction approach based on wavelet domain for superresolution image reconstruction of infra-red (IR) sequences. Minimizing the regularization cost function in wavelet domain forms a multi-scale high-resolution estimate. The effects of noise are incorporated into the iterative process in the proposed method. The estimation errors in high- and low-frequency bands are processed separately to solve the problem of variable correlations of observed images and slow convergence. The proposed approach was tested on the infrared aerial image sequences provided by Defence Research Establishment in valcartier. Experiment results show that a significant increase in the spatial resolution can be achieved by the proposed approach while the noise is smoothed out.

关键词： wavelet domain superresolution reconstruction restoration infrared image sequences

来源：评论

学校读者我要写书评

暂无评论

Hierarchical adaptive regularisation method for depth extraction from planar recording of 3D-integral images

Hierarchical adaptive regularisation method for depth extrac...

引用

IEEE International conference on Acoustics, Speech, and Signal Processing

作者： Manolache, S McCormick, M Kung, SY De Montfort Univ Dept Engn & Technol Leicester LE1 9BH Leics England

ISBN: (纸本)0780370414

The paper presents a novel algorithm for object space reconstruction from the planar (2D) recorded data set of a 3D-integral image. The integral imaging system is described and the associated point spread function is given. The space data extraction is formulated as an inverse problem, which proves ill-conditioned, and tackled by using a hierarchical multiresolution strategy and imposing additional conditions to the sought solution. The hierarchisation strategy and the two-phase adaptive constrained 3D-reconstruction algorithm based on the use of two sigmoid functions are presented. Finally, illustrative simulation results are given.

关键词： image reconstruction

来源：评论

学校读者我要写书评

暂无评论

from sinograms to surfaces: A direct approach to the segmentation of tomographic data 4th

引用

4th International conference on Medical image Computing and Computer-Assisted Intervention, MICCAI 2001

作者： Elangovan, vidya Whitaker, Ross T. School of Computing University of Utah Salt Lake CityUT United States

ISBN: (纸本)3540426973

Under ideal circumstances the problem of tomographic reconstruction is well-posed, and measured data are sufficient to obtain accurate estimates of volume densities. In such cases segmentation and surface estimation from the reconstructed volume are justified. In other situations the reconstructed volumes are not suitable for subsequent segmentation. This can happen in the case of incomplete sinograms, noise in the measurement process, or misregistration of the views. This paper presents a direct approach to the segmentation of incomplete and noisy tomographic data. The strategy is to impose a fairly simple model on the data, and treat segmentation as a problem of estimating the interface between two substances of somewhat homogeneous density. The segmentation is achieved by simultaneously deforming a surface model and updating density parameters in order to achieve a best fit between the projected model and the input sinograms. The deformation is implemented with level-set surface models, calculated at the resolution of the input data. Several computational innovations make the approach feasible with state-of-the-art computers. The usefulness of the approach is demonstrated by reconstructing the shape of spiny dendrites from electron microscope tomographic data. © Springer-verlag Berlin Heidelberg 2001.

关键词： Deformation

来源：评论

学校读者我要写书评

暂无评论

Three-dimensional total variation norm for SPECT reconstruction

引用

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 2001年第1-2期471卷 98-102页

作者： Persson, M Bone, D Elmqvist, H Karolinska Inst Div Med Engn S-14186 Huddinge Sweden Karolinska Hosp Dept Clin Physiol S-10401 Stockholm Sweden

The total variation (Tv) norm has been described in literature as a method for reducing noise in two-dimensional (2D) images. At the same time. the Tv-norm is very good at recovering edges in images, without introducing ringing or edge artefacts. It has also been proposed as a 2D regularisation function in Bayesian reconstruction, implemented in an expectation maximisation (EM) algorithm, and called Tv-EM. The Tv-EM was developed for 2D SPECT imaging, and the algorithm is capable of smoothing noise while maintaining edges without introducing artefacts. We have extended the Tv-norm to take into account the third spatial dimension, and developed an iterative EM algorithm based on the three-dimensional (3D) Tv-norm, which we call Tv3D-EM. This takes into account the correlation between transaxial sections in SPECT, due to system resolution. We have compared the 2D and 3D algorithms using reconstructed images from simulated projection data. Phantoms used were a homogeneous sphere, and a 3D head phantom based on the Shepp-Logan phantom. The Tv3D-EM algorithm yielded somewhat lower noise levels than Tv-EM. The noise in the Tv3D-EM had similar correlation in transaxial and longitudinal sections, which was not the case for Tv-EM, or any 2D reconstruction method. In particular, longitudinal sections from Tv3D-EM were perceived as less noisy when compared to Tv-EM. The use of 3D reconstruction should also be advantageous if compensation for distant dependent collimator blurring is incorporated in the iterative algorithm. (C) 2001 Elsevier Science B.v. All rights reserved.

关键词： SPECT tomography image reconstruction scintigraphy algorithm simulation

来源：评论

学校读者我要写书评

暂无评论

Multiscale models for data processing: An experimental sensitivity analysis

引用

IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2001年第4期50卷 995-1002页

作者： Ferrari, S Borghese, NA Piuri, v Politecn Milan Dept Elect & Informat I-20133 Milan Italy CNR San Raffaele Sci Inst Ist Neurosci & Bioimmagini MAVRLab Human Mot Anal & Virtual RealLITA Segrate MI Italy Univ Milan Dept Informat Technol Crema CR Italy

Hierarchical radial basis functions (HRBFs) networks have been recently introduced as a tool for adaptive multiscale image reconstruction from range data. These are based on local operation on the data and are able to give a sparse approximation. In this paper, HRBFs are reframed for the regular sampling case, and they are compared with wavelet decomposition. Results show that HRBFs, thanks to their constructive approach to approximation, are much more tolerant on errors in the parameters when errors occur in the configuration phase.

关键词： basis functions function spaces iterative decomposition multiresolution analysis multiscale signal decomposition quantization error RBF networks robustness sensitivity signal processing wavelets

来源：评论

学校读者我要写书评

暂无评论

Multiscale models for data processing: An experimental sensitivity analysis

Multiscale models for data processing: An experimental sensi...

引用

Instrumentation and Measurement Technology conference (IMTC 2000)

来源：评论

学校读者我要写书评

暂无评论

Performance evaluation of stereo for tele-presence

Performance evaluation of stereo for tele-presence

引用

8th International conference on Computer vision

作者： Mulligan, J. Isler, v. Daniilidis, K. University of Pennsylvania GRASP Laboratory Philadelphia PA United States

In an immersive tele-presence environment a 3D remote real scene is projected from the viewpoint of the local user. This 3D world is acquired through stereo reconstruction at the remote site. In this paper, we start a performance analysis of stereo algorithms with respect to the task of immersive visualization. As opposed to usual monocular image based rendering, we are also interested in the depth error in novel views because our rendering is stereoscopic. We describe an evaluation test-bed which provides a world-wide first available set of registered dense "ground-truth" laser data and image data from multiple views. We establish metrics for novel depth views that reflect discrepancies both in the image and in 3D-space. It is well known that stereo performance is affected by both erroneous matching as well as incorrect depth triangulation. We experimentally study the effects of occlusion and low texture on the distributions of the error metrics. Then, we algebraically predict the behavior of depth and novel projection error as a function of the camera set-up and the error in the disparity. These are first steps towards building a laboratory for psychophysical judgement of depth estimates which is the ultimate performance test of tele-presence stereo.

关键词： Stereo vision

来源：评论

学校读者我要写书评

暂无评论

Synthesizing invariant 3-D rigid scattering centers

Synthesizing invariant 3-D rigid scattering centers

引用

conference on Algorithms for Synthetic Aperture Radar imagery vIII

作者： Arnold, DG Claypool, R velten, v Sturtz, K USAF Res Lab AFRL SNAT Wright Patterson AFB OH 45433 USA

ISBN: (纸本)0819440779

Automatic Target Recognition (ATR) is difficult in general., but especially with RADAR. However, the problem can be greatly simplified by using the 3-D reconstruction techniques presented at SPIE1,2 the previous 2 years. Now, instead of matching seemingly random signals in I-D or 2-D, one must match scattering centers in 3-D. This method tracks scattering centers through an image collection sequence that would typically be used for SAR image formation. A major difference is that this approach naturally allows object motion (in fact the more the object moves, the better) and the resulting 'image' is a 3-D set of scattering centers! This paper discusses a preliminary study into extracting the scattering centers directly from synthetic data to build a database in anticipation of comparing the relative separability of these reconstructed scattering centers against more traditional approaches for doing ATR.

关键词： RADAR ATR invariants recognition reconstruction feature extraction scattering center

来源：评论

学校读者我要写书评

暂无评论

3D hand pose reconstruction using specialized mappings

3D hand pose reconstruction using specialized mappings

引用

8th International conference on Computer vision

作者： Rosales, R. Athitsos, v. Sigal, L. Sclaroff, S. Boston University Computer Science Department 111 Cummington St. Boston MA 02215 United States

A system for recovering 3D hand pose from monocular color sequences is proposed. The system employs a non-linear supervised learning framework, the specialized mappings architecture (SMA), to map image features to likely 3D hand poses. The SMA's fundamental components area a set of specialized forward mapping functions, and a single feedback matching function. The forward functions are estimated directly from training data, which is our case are examples of hand joint configurations and their corresponding visual features. The joint angle data in the training set is obtained via a CyberGlove, a glove with 22 sensors that monitor the angular motions of the palm and fingers. In training, the visual features are generated using a computer graphics module that renders the hand from arbitrary viewpoints given the 22 joint angles. The viewpoint is encoded by two real values, therefore 24 real values represent a hand pose. We test our system both on synthetic sequences and on sequences taken with a color camera. The system automatically detects and tracks both hands of the user, calculates the appropriate features, and estimates the 3D hand joint angles and viewpoint from those features. Results are encouraging given the complexity of the task.

关键词： image reconstruction

来源：评论

学校读者我要写书评

暂无评论

A method of attenuation map and emission activity reconstruction from emission data

A method of attenuation map and emission activity reconstruc...

引用

1999 Medical Imaging conference (MIC)

作者： Panin, v.Y. Zeng, G.L. Gullberg, G.T. University of Utah Department of Radiology 729 Arapeen Dr Salt Lake City UT 84108-1218 United States

An iterative algorithm that reconstructs the attenuation map and emission activity distribution from SPECT emission data is proposed. The algorithm is based on the quasilinearized attenuated Radon transform. At each iteration of the algorithm, emission activity distribution is reconstructed using the attenuation map from the previous iteration. Then, the attenuation map is estimated by using the current emission image. To effectively locate the attenuation map within a possible class of solutions the attenuation map is constrained by an optimal basis set, which is derived from a cross-correlation of a priori images known as a "knowledge set." Computer simulations show that the proposed algorithm has the capability to reconstruct the emission activity distribution and the transmission map without the use of transmission measurements. The proposed method has been tested using clinically acquired data.

关键词： Computerized tomography

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：