检索结果-内蒙古大学图书馆

作者： Lladó, X. Petrou, M. Centre for Vision Speech and Signal Processing University of Surrey Guildford GU2 7XH United Kingdom Computer Vision and Robotics Group Institute of Informatics and Applications University of Girona 17071 Girona Spain

The purpose of this work is to analyse what happens to the surface information when the image resolution is modified. We deduce how the same surface appears if seen from different distances. Using 4-source Colour Photometric Stereo, which provides the surface shape and colour information, a method for predicting how surface texture looks like when changing the distance of the camera is presented. We demonstrate this technique by classifying textured surfaces seen from different distances than the textured surfaces in the database. © 2002 IEEE.

关键词： Classification (of information)

来源：评论

学校读者我要写书评

暂无评论

Active regions for colour texture segmentation integrating region and boundary information

Active regions for colour texture segmentation integrating r...

引用

IEEE International Conference on Image Processing

作者： X. Munoz J. Freixenet X. Cufi J. Marti Computer Vision and Robotics Group. Institute of Informatics and Applications University of Girona Girona Spain

In this paper a colour texture segmentation method, which unifies region and boundary information, is proposed. The algorithm uses a coarse detection of the perceptual (colour and texture) edges of the image to adequately place and initialise a set of active regions. Colour texture of regions is modelled by the conjunction of non-parametric techniques of kernel density estimation (which allow to estimate the colour behaviour) and classical co-occurrence matrix based texture features. Therefore, region information is defined and accurate boundary information can be extracted to guide the segmentation process. Regions concurrently compete for the image pixels in order to segment the whole image taking both information sources into account. Furthermore, experimental results are shown which prove the performance of the proposed method.

关键词： Image segmentation Proposals Data mining Image edge detection Pixel computer vision Robot vision systems informatics Application software Kernel

来源：评论

学校读者我要写书评

暂无评论

A rectangle-intersection algorithm with limited resource requirements

A rectangle-intersection algorithm with limited resource req...

引用

10th IEEE International Conference on computer and Information Technology, CIT-2010, 7th IEEE International Conference on Embedded Software and Systems, ICESS-2010, 10th IEEE Int. Conf. Scalable Computing and Communications, ScalCom-2010

作者： Dévai, Frank Neumann, László Department of Informatics London South Bank University London United Kingdom ICREA Computer Vision and Robotics Group University of Girona Spain

ISBN: (纸本)9780769541082

It is demonstrated that power-efficient software also requires simplicity and the use of elementary data structures in addition to asymptotically optimal CPU and memory requirements. Though in the past few decades much effort has been devoted to reporting all k intersecting pairs in a planar set of n iso-oriented rectangles, all the known algorithms using elementary data structures, such as linked lists, are either not optimal, report some intersections repeatedly or fail to report some altogether. A simpler algorithm is proposed that uses only linear arrays and that takes O(n log n + k) time and O(n) space, which are the best possible under the algebraic RAM model of computation. The algorithm is designed for systems with limited resources, such as mobile 3D graphics, and can be implemented in less than 100 lines of Java code. © 2010 Crown Copyright.

关键词： Data structures

来源：评论

学校读者我要写书评

暂无评论

ROV-Aided Dam Inspection: Practical Results

引用

IFAC Proceedings Volumes 2003年第21期36卷 271-274页

作者： Joan Batlle Tudor Nicosevici Rafael Garcia Marc Carreras Computer Vision and Robotics Group Institute of Informatics and Applications University of Girona E.P.S. 17071 Girona Spain

Nowadays Unmanned Underwater Vehicles (UUVs) are used in a growing number of underwater missions, mostly inspections of different types of installations such as: telecommunication cables, pipes or oil extraction installations. A field where UUVs are still starting to prove their utility is dam inspection. This paper presents details our first approach in dam inspection. A set of experiments carried out at a dam in Romania is described. Advantages and drawbacks of using a small-class underwater vehicle are analyzed for this type of missions.

关键词： computer vision teleoperation fault detection motion estimation

来源：评论

学校读者我要写书评

暂无评论

A new approach to segmentation based on fusing circumscribed contours, region growing and clustering

A new approach to segmentation based on fusing circumscribed...

引用

IEEE International Conference on Image Processing

作者： X. Munoz X. Cufi J. Freixenet J. Marti Computer Vision and Robotics Group Institute of Informatics and Applications University of Girona Catalonia Spain

ISBN: (纸本)0780362977

One of the major problems in machine vision is the segmentation of images of natural scenes. This paper presents a new proposal for the image segmentation problem which has been based on the integration of edge and region information. The main contours of the scene are detected and used to guide the posterior region growing process. The algorithm places a number of seeds at both sides of a contour allowing stating a set of concurrent growing processes. A previous analysis of the seeds permits to adjust the homogeneity criterion to the regions's characteristics. A new homogeneity criterion based on clustering analysis and convex hull construction is proposed.

关键词： Image segmentation Image edge detection Layout Clustering algorithms computer vision Robot vision systems informatics Application software Machine vision Proposals

来源：评论

学校读者我要写书评

暂无评论

Use of decision trees in colour feature selection. Application to object recognition in outdoor scenes

Use of decision trees in colour feature selection. Applicati...

引用

IEEE International Conference on Image Processing

作者： J. Freixenet X. Llado J. Marti X. Cufi Computer Vision and Robotics Group Institute of Informatics and Applications University of Girona Catalonia Spain

A new method for the automated selection of colour features is described. The algorithm consists of two stages of processing. In the first, a complete set of colour features is calculated for every object of interest in an image. In the second stage, each object is mapped into several n-dimensional feature spaces in order to select the feature set with the smallest variables able to discriminate the remaining objects. The evaluation of the discrimination power for each concrete subset of features is performed by means of decision trees composed of linear discrimination functions. This method can provide valuable help in outdoor scene analysis where no colour space has been demonstrated as being the most suitable. Experiment results recognizing objects in outdoor scenes are reported.

关键词： Decision trees Object recognition Layout Application software Geometry computer vision Robot vision systems robotics and automation informatics Concrete

来源：评论

学校读者我要写书评

暂无评论

Calibration of A Structured Light-Based Stereo Catadioptric Sensor

Calibration of A Structured Light-Based Stereo Catadioptric ...

引用

IEEE computer Society Conference on computer vision and Pattern Recognition Workshops (CVPRW)

作者： Radu Orghidan Joaquim Salvi El Mustapha Mouaddib Computer Vision and Robotics Group Institute of Informatics and Applications Girona Catalonia Spain

Catadioptric sensors are combinations of mirrors and lenses made in order to obtain a wide field of view. In this paper we propose a new sensor that has omnidirectional viewing ability and it also provides depth information about the nearby surrounding. The sensor is based on a conventional camera coupled with a laser emitter and two hyperbolic mirrors. Mathematical formulation and precise specifications of the intrinsic and extrinsic parameters of the sensor are discussed. Our approach overcomes limitations of the existing omni-directional sensors and eventually leads to reduced costs of production.

关键词： Mirrors Cameras Mathematical model Robot sensing systems Equations Laser modes Lasers

来源：评论

学校读者我要写书评

暂无评论

Policy Gradient Based Reinforcement Learning for Real Autonomous Underwater Cable Tracking

Policy Gradient Based Reinforcement Learning for Real Autono...

引用

2008 IEEE/RSJ International Conference on Intelligent Robots and Systems, Pages 3133-3660

作者： Andres El-Fakdi Marc Carreras Computer Vision and Robotics Group (VICOROB) Institute of Informatics and Applications University of Girona 17074 Girona Spain

ISBN: (纸本)9781424420575

This paper proposes a field application of a high-level Reinforcement Learning (RL) control system for solving the action selection problem of an autonomous robot in cable tracking task. The learning system is characterized by using a Direct Policy Search method for learning the internal state/action mapping. Policy only algorithms may suffer from long convergence times when dealing with real robotics. In order to speed up the process, the learning phase has been carried out in a simulated environment and, in a second step, the policy has been transferred and tested successfully on a real robot. Future steps plan to continue the learning process on-line while on the real robot while performing the mentioned task. We demonstrate its feasibility with real experiments on the underwater robot ICTINEU~(AUV).

关键词： Robots Underwater cables Vehicles Power cables Artificial neural networks Surges Robot sensing systems

来源：评论

学校读者我要写书评

暂无评论

Image Mosaicking for Estimating the Motion of an Underwater Vehicle

引用

IFAC Proceedings Volumes 2000年第21期33卷 147-152页

作者： Rafael García Xevi Cufí Lluís Pacheco Computer Vision and Robotics Group Institute of Informatics and Applications University of Girona Edifici Politècnica II Escola Politecnica Superior 17071 Girona Spain

A composite image constructed by combining a set of smaller images is known as mosaic. Mosaics of the ocean floor are very useful in undersea exploration, creation of visual maps, navigation, etc. A feature-based mosaicking method is proposed, based on textural parameters of certain parts of the image. Textures significantly help in the identification of given features of the image. The tracking of these features over time solves the matching problem in consecutive frames. The correspondence is established with the aid of a cross-correlation algorithm, applied to the colour components of the image in the HSI space. Once the correspondence has been found a displacement vector is obtained relating the features of two images of the sequence. The motion parameters between consecutive frames are estimated through an error minimisation technique. Once the best transformation between two frames has been found, images are warped together composing the mosaic, and information about the vehicle motion is recovered. The experimental results on real images show the effectiveness of the proposed method.

关键词： computer vision Motion estimation Autonomous vehicles Image registration Robot navigation Marine Systems

来源：评论

学校读者我要写书评

暂无评论

Implementation of a Real-Time Target Tracking Behaviour Using Video Sensors

引用

IFAC Proceedings Volumes 2001年第7期34卷 517-521页

作者： V. lla P. Ridao J.De La Cruz J. Batlle Computer Vision and Robotics Group Institute of Informatics and Applications. University of Girona Edifici Politecnica ll Campus Montilivi 17071 Girona Spain

Using software OS, real-time operation is constrained by acquisition and preprocessing tasks of input signals. In this way, this paper presents an implementation of a real time target tracking behaviour, from snapped images of the environment, as an example of how to take advantage of real-time hardware devices as a helpful systems for control architectures. A specific board based on FPGA/DSP processors has been used in order to reach this goal. The system has been thought for a marine and underwater environment and it has been tested using GARBI autonomous underwater vehicle. The implemented behaviours allow the robot to navigate autonomously and follow a diver.

关键词： behaviour binary image autonomous vehicle computer control

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：