检索结果-内蒙古大学图书馆

A color image segmentation approach for content-based image retrieval

PATTERN RECOGNITION 2007年第4期40卷 1318-1325页

作者： Ozden, Mustafa Polat, Ediz Kirikkale Univ Dept Elect & Elect Engn TR-71450 Kirikkale Turkey

This paper describes a new color image segmentation method based on low-level features including color, texture and spatial information. The mean-shift algorithm with color and spatial information in color image segmentation is in general successful, however, in some cases, the color and spatial information are not sufficient for superior segmentation. The proposed method addresses this problem and employs texture descriptors as an additional feature. The method uses wavelet frames that provide translation invariant texture analysis. The method integrates additional texture feature to the color and spatial space of standard mean-shift segmentation algorithm. The new algorithm with high dimensional extended feature space provides better results than standard mean-shift segmentation algorithm as shown in experimental results. (c) 2006 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved.

关键词： image segmentation mean-shift algorithm discrete wavelet frames texture segmentation

来源：评论

学校读者我要写书评

暂无评论

Welfare interface implementation using multiple facial features tracking for the disabled people

引用

PATTERN RECOGNITION LETTERS 2008年第13期29卷 1784-1796页

作者： Shin, Yunhee Ju, Jin Sun Kim, Eun Yi Konkuk Univ Sch Internet & Multimedia Engn Dept Adv Technol Fus Seoul 143701 South Korea

This paper proposes a multiple facial feature interface that allows disabled users with various disabilities to implement different mouse operations. Using a regular PC camera, the proposed system detects the user's eye and mouth movements, and then interprets the communication intent to control the computer. Here, mouse movements are implemented based on the user's eye movements, while clicking events are implemented based on the user's mouth shapes, such as opening/closing. The proposed system is composed of three modules: facial feature detector, facial feature tracker, and mouse controller. The facial region is initially identified using a skin-color model and connected-component (CC) analysis. Thereafter, the eye regions are localized using a neural network (NN)-based texture classifier that discriminates the facial region into eye class and non-eye class, then the mouth region is localized using an edge detector. Once the eye and mouth regions are localized, they are continuously and accurately tracking using a mean-shift algorithm and template matching. respectively. Based on the tracking results, the mouse movements and clicks are then implemented. To assess the validity of the proposed method, it was applied to three applications: a web browser, 'spelling board', and the game 'catching-a-bird'. The two test groups involved 34 users, and the results showed that the proposed system could be efficiently and effectively applied as a user-friendly and convenient communication device. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

关键词： real-time facial feature tracking neural network mean-shift algorithm template matching video-based human-computer interface

来源：评论

学校读者我要写书评

暂无评论

Real-time density and mode estimation with application to time-dynamic mode tracking

引用

JOURNAL OF COMPUTATIONAL AND GRAPHICAL STATISTICS 2006年第1期15卷 82-100页

作者： Hall, P Müller, HG Wu, PS Australian Natl Univ Ctr Math & Its Applicat Canberra ACT 0200 Australia Univ Calif Davis Dept Stat Davis CA 95616 USA Lehigh Univ Dept Math Bethlehem PA 18015 USA

We introduce a nonparametric time-dynamic kernel type density estimate for the situation where an underlying multivariate distribution evolves with time. Based on this time-dynamic density estimate, we propose nonparametric estimates for the time-dynamic mode of the underlying distribution. Our estimators involve boundary kernels for the time dimension so that the estimator is always centered at current time, and multivariate kernels for the spatial dimension of the time-evolving distribution. Under certain mild conditions, the asymptotic behavior of density and mode estimators, especially their uniform convergence in both time and space, is derived. A time-dynamic algorithm for mode tracking is proposed, including automatic bandwidth choices, and is implemented via a mean update algorithm. Simulation studies and real data illustrations demonstrate that the proposed methods work well in practice.

关键词： boundary kernel mean-shift algorithm modal evolution nonparametric estimation spatio-temporal modeling uniform convergence

来源：评论

学校读者我要写书评

暂无评论

γ-SUP: A CLUSTERING algorithm FOR CRYO-ELECTRON MICROSCOPY IMAGES OF ASYMMETRIC PARTICLES

引用

ANNALS OF APPLIED STATISTICS 2014年第1期8卷 259-285页

作者： Chen, Ting-Li Hsieh, Dai-Ni Hung, Hung Tu, I-Ping Wu, Pei-Shien Wu, Yi-Ming Chang, Wei-Hau Huang, Su-Yun Acad Sinica Inst Stat Sci Taipei 11529 Taiwan Natl Taiwan Univ Inst Epidemiol & Prevent Med Taipei 10055 Taiwan Duke Univ Dept Biostat & Bioinformat Durham NC 27710 USA

Cryo-electron microscopy (cryo-EM) has recently emerged as a powerful tool for obtaining three-dimensional (3D) structures of biological macromolecules in native states. A minimum cryo-EM image data set for deriving a meaningful reconstruction is comprised of thousands of randomly orientated projections of identical particles photographed with a small number of electrons. The computation of 3D structure from 2D projections requires clustering, which aims to enhance the signal to noise ratio in each view by grouping similarly oriented images. Nevertheless, the prevailing clustering techniques are often compromised by three characteristics of cryo-EM data: high noise content, high dimensionality and large number of clusters. Moreover, since clustering requires registering images of similar orientation into the same pixel coordinates by 2D alignment, it is desired that the clustering algorithm can label misaligned images as outliers. Herein, we introduce a clustering algorithm gamma-SUP to model the data with a q-Gaussian mixture and adopt the minimum gamma-divergence for estimation, and then use a self-updating procedure to obtain the numerical solution. We apply gamma-SUP to the cryo-EM images of two benchmark macromolecules, RNA polymerase II and ribosome. In the former case, simulated images were chosen to decouple clustering from alignment to demonstrate gamma-SUP is more robust to misalignment outliers than the existing clustering methods used in the cryo-EM community. In the latter case, the clustering of real cryo-EM data by our gamma-SUP method eliminates noise in many views to reveal true structure features of ribosome at the projection level.

关键词： Clustering algorithm cryo-EM images gamma-divergence k-means mean-shift algorithm multilinear principal component analysis q-Gaussian distribution robust statistics self-updating process

来源：评论

学校读者我要写书评

暂无评论

Clustering of Image Covariance Matrixes on Lie Group Manifold

引用

AUTOMATIC CONTROL AND COMPUTER SCIENCES 2024年第2期58卷 209-215页

作者： Zheng, Mingliang Taihu Univ Wuxi Sch Mech & Elect Engn Wuxi 214064 Jiangsu Peoples R China Huainan Normal Univ Sch Mech & Elect Engn Huainan 232038 Peoples R China

An image clustering method based on covariance matrix and mean-shift algorithm on Lie group manifold is proposed. Firstly, according to the extracted multidimensional correlation features of image, the covariance matrixes are calculated to form a Lie group manifold. Secondly, by using the mapping relationship between Lie group and Lie algebra, the steps of covariance matrixes clustering based on mean-shift algorithm on Lie group are established. Finally, the example verifies that the mean-shift algorithm on Lie group manifold can better obtain the clustering information of the image covariance matrixes, and the average accuracy of image classification is 95.80%, which improves accuracy by 3.1% compared to traditional algorithms. Moreover, if the kernel function, bandwidth and threshold are set up reasonably, the image clustering is more efficient and accurate. For the unit Gaussian kernel function, the optimal bandwidth is 1.2, the optimal threshold is 0.8. It provides an algorithmic basis for the application of Lie group machine learning in high-precision automatic target clustering.

关键词： image clustering covariance matrix Lie group manifold mean-shift algorithm

来源：评论

学校读者我要写书评

暂无评论

Nonparametric modal regression in the presence of measurement error

引用

ELECTRONIC JOURNAL OF STATISTICS 2016年第2期10卷 3579-3620页

作者： Zhou, Haiming Huang, Xianzheng Northern Illinois Univ Div Stat De Kalb IL 60115 USA Univ South Carolina Dept Stat Columbia SC 29208 USA

In the context of regressing a response Y on a predictor X, we consider estimating the local modes of the distribution of Y given X = x when X is prone to measurement error. We propose two nonparametric estimation methods, with one based on estimating the joint density of (X, Y) in the presence of measurement error, and the other built upon estimating the conditional density of Y given X = x using error-prone data. We study the asymptotic properties of each proposed mode estimator, and provide implementation details including the mean-shift algorithm for mode seeking and bandwidth selection. Numerical studies are presented to compare the proposed methods with an existing mode estimation method developed for error-free data naively applied to error-prone data.

关键词： Bandwidth selection deconvoluting kernel Fourier transform local mode mean-shift algorithm

来源：评论

学校读者我要写书评

暂无评论

Constructing interactive multi-view videos based on image-based rendering

引用

INTERNATIONAL JOURNAL OF COMPUTATIONAL SCIENCE AND ENGINEERING 2015年第4期10卷 402-414页

作者： Chang, Shih-Ming Tsai, Joseph C. Yen, Shwu-Huey Shih, Timothy K. Tamkang Univ Dept Comp Sci & Informat Engn New Taipei 25137 Taiwan Natl Cent Univ Dept Comp Sci & Informat Engn Taoyuan 30201 Taiwan

In this paper, we use image-based rendering (IBR) to develop a scene rotation mechanism. We shot several images in the same scene and computed the angles between images. A video is then composed, allowing users to select viewing angles when the video is playing. We made three kinds of assumptions that may affect the resulting video, and proved our assumptions by a series of experiments. Finally, we use video of realistic scenario and produce interactive video by the proposed method. The contribution also includes techniques to compute geometric parameters of the scene from one or more images.

关键词： SIFT algorithm mean-shift algorithm homography matrix image-based rendering IBR

来源：评论

学校读者我要写书评

暂无评论

Interval-censored unimodal kernel density estimation via data sharpening

引用

JOURNAL OF STATISTICAL COMPUTATION AND SIMULATION 2017年第10期87卷 2023-2037页

作者： Becker, Devan G. Braun, W. John White, Bethany J. G. Univ Western Ontario Stat & Actuarial Sci London ON Canada Univ British Columbia Okanagan Stat 1177 Res Rd Kelowna BC V1V 1V7 Canada Univ Toronto Stat Sci Toronto ON Canada

In this paper, we extend Choi and Hall's [Data sharpening as a prelude to density estimation. Biometrika. 1999;86(4):941-947] data sharpening algorithm for kernel density estimation to interval-censored data. Data sharpening has several advantages, including bias and mean integrated squared error (MISE) reduction as well as increased robustness to bandwidth misspecification. Several interval metrics are explored for use with the kernel function in the data sharpening transformation. A simulation study based on randomly generated data is conducted to assess and compare the performance of each interval metric. It is found that the bias is reduced by sharpening, often with little effect on the variance, thus maintaining or reducing overall MISE. Applications involving time to onset of HIV and running distances subject to measurement error are used for illustration.

关键词： Nonparametric estimation shape constraints mean-shift algorithm

来源：评论

学校读者我要写书评

暂无评论

DESIGN AND DEVELOPMENT OF AN ON-BOARD AUTONOMOUS VISUAL TRACKING SYSTEM FOR UNMANNED AERIAL VEHICLES

引用

AVIATION 2017年第3期21卷 83-91页

作者： Kemsaram, Narsimlu Thatiparti, Venkata Rajini Kanth Guntupalli, Devendra Rao Kuvvarapu, Anil JNT Univ Dept Comp Sci & Engn Hyderabad 500085 Andhra Prades India SNIST Dept Comp Sci & Engn Hyderabad 501301 Andhra Prades India Cyient Ltd Dept Informat Syst Hyderabad 500081 Andhra Prades India Univ Michigan Dept Comp Sci Ann Arbor MI 48109 USA

This paper proposes the design and development of an on-board autonomous visual tracking system (AVTS) for unmanned aerial vehicles (UAV). A prototype of the proposed system has been implemented in MATLAB/ Simulink for simulation purposes. The proposed system contains GPS/INS sensors, a gimbaled camera, a multi-level autonomous visual tracking algorithm, a ground stationary target (GST) or ground moving target (GMT) state estimator, a camera control algorithm, a UAV guidance algorithm, and an autopilot. The on-board multi-level autonomous visual tracking algorithm acquires the video frames from the on-board camera and calculates the GMT pixel position in the video frame. The on-board GMT state estimator receives the GMT pixel position from the multi-level autonomous visual tracking algorithm and estimates the current position and velocity of the GMT with respect to the UAV. The on-board non-linear UAV guidance law computes the UAV heading velocity rates and sends them to the autopilot to steer the UAV in the desired path. The on-board camera control law computes the control command and sends it to the camera's gimbal controller to keep the GMT in the camera's field of view. The UAV guidance law and camera control law have been integrated for continuous tracking of the GMT. The on-board autopilot is used for controlling the UAV trajectory. The simulation of the proposed system was tested with a flight simulator and the UAV's reaction to the GMT was observed. The simulated results prove that the proposed system tracks a GST or GMT effectively.

关键词： autonomous visual tracking system aviator visual design simulator cam-shift algorithm extended Kalman filter estimator ground moving target ground stationary target mean-shift algorithm micro aerial vehicles unmanned aircraft systems unmanned aerial vehicles

来源：评论

学校读者我要写书评

暂无评论

Moving Up the Cluster Tree with the Gradient Flow*

引用

SIAM JOURNAL ON MATHEMATICS OF DATA SCIENCE 2023年第2期5卷 400-421页

作者： Arias-Castro, Ery Qiao, Wanli Univ Calif San Diego Dept Math San Diego CA 92093 USA George Mason Univ Dept Stat Fairfax VA 22030 USA

This paper establishes a strong correspondence between two important clustering approaches that emerged in the 1970s: clustering by level sets or cluster tree as proposed by Hartigan, and clustering by gradient lines or gradient flow as proposed by Fukunaga and Hostetler. This correspondence is drawn by showing that the gradient ascent flow provides a natural way to move up the cluster tree.

关键词： clustering level sets cluster tree gradient lines gradient flow mean-shift algorithm dynamical systems

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：