• Title/Summary/Keyword: Spatial object

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Unsupervised Segmentation of Objects using Genetic Algorithms (유전자 알고리즘 기반의 비지도 객체 분할 방법)

  • 김은이;박세현
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.41 no.4
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    • pp.9-21
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    • 2004
  • The current paper proposes a genetic algorithm (GA)-based segmentation method that can automatically extract and track moving objects. The proposed method mainly consists of spatial and temporal segmentation; the spatial segmentation divides each frame into regions with accurate boundaries, and the temporal segmentation divides each frame into background and foreground areas. The spatial segmentation is performed using chromosomes that evolve distributed genetic algorithms (DGAs). However, unlike standard DGAs, the chromosomes are initiated from the segmentation result of the previous frame, then only unstable chromosomes corresponding to actual moving object parts are evolved by mating operators. For the temporal segmentation, adaptive thresholding is performed based on the intensity difference between two consecutive frames. The spatial and temporal segmentation results are then combined for object extraction, and tracking is performed using the natural correspondence established by the proposed spatial segmentation method. The main advantages of the proposed method are twofold: First, proposed video segmentation method does not require any a priori information second, the proposed GA-based segmentation method enhances the search efficiency and incorporates a tracking algorithm within its own architecture. These advantages were confirmed by experiments where the proposed method was success fully applied to well-known and natural video sequences.

A Experimental Study on the Translation from Korean Digital Topographic Maps to Distributed Objects (수치지형도의 객체화 변환에 관한 연구)

  • 황철수
    • Spatial Information Research
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    • v.7 no.2
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    • pp.255-269
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    • 1999
  • This is an experimental study to translate the Korean digital topographic maps into distributable information-hide objects, which are designed with object-oriented development's key features ; encapsulation, polymorphism, inheritance, In order to achieve this goal , the characteristics of the data mode and inter-relationships of digital topographic maps are investigated . As a result, it is revealed that the current Korean digital topographic maps, which is organized into so many individual layers of mixed spatial and attributed data, have to explicit and concrete hierarchies in spatial data model and data definition . Due to this limitation , data layer stage and object class stage are integrated. And ISCO(the is-computer -of relationships) mechanism is mainly used to develop the objects of digital topogrpahic maps, which is implemented with spatial primitive classes. the designed objects are coded with JAVA and then testified in web interface.

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Moving Object Contour Detection Using Spatio-Temporal Edge with a Fixed Camera (고정 카메라에서의 시공간적 경계 정보를 이용한 이동 객체 윤곽선 검출 방법)

  • Kwak, Jae-Ho;Kim, Whoi-Yul
    • Journal of Broadcast Engineering
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    • v.15 no.4
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    • pp.474-486
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    • 2010
  • In this paper, we propose a new method for detection moving object contour using spatial and temporal edge. In general, contour pixels of the moving object are likely present around pixels with high gradient value along the time axis and the spatial axis. Therefore, we can detect the contour of the moving objects by finding pixels which have high gradient value in the time axis and spatial axis. In this paper, we introduce a new computation method, termed as temporal edge, to compute an gradient value along the time axis for any pixel on an image. The temporal edge can be computed using two input gray images at time t and t-2 using the Sobel operator. Temporal edge is utilized to detect a candidate region of the moving object contour and then the detected candidate region is used to extract spatial edge information. The final contour of the moving object is detected using the combination of these two edge information, which are temporal edge and spatial edge, and then the post processing such as a morphological operation and a background edge removing procedure are applied to remove noise regions. The complexity of the proposed method is very low because it dose not use any background scene and high complex operation, therefore it can be applied to real-time applications. Experimental results show that the proposed method outperforms the conventional contour extraction methods in term of processing effort and a ghost effect which is occurred in the case of entropy method.

Precision Analysis of the STOMP(FW) Algorithm According to the Spatial Conceptual Hierarchy (공간 개념 계층에 따른 STOMP(FW) 알고리즘의 정확도 분석)

  • Lee, Yon-Sik;Kim, Young-Ja;Park, Sung-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.12
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    • pp.5015-5022
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    • 2010
  • Most of the existing pattern mining techniques are capable of searching patterns according to the continuous change of the spatial information of an object but there is no constraint on the spatial information that must be included in the extracted pattern. Thus, the existing techniques are not applicable to the optimal path search between specific nodes or path prediction considering the nodes that a moving object is required to round during a unit time. In this paper, the precision of the path search according to the spatial hierarchy is analyzed using the Spatial-Temporal Optimal Moving Pattern(with Frequency & Weight) (STOPM(FW)) algorithm which searches for the optimal moving path by considering the most frequent pattern and other weighted factors such as time and cost. The result of analysis shows that the database retrieval time is minimized through the reduction of retrieval range applying with the spatial constraints. Also, the optimal moving pattern is efficiently obtained by considering whether the moving pattern is included in each hierarchical spatial scope of the spatial hierarchy or not.

Magnetic Resonance Imaging of a Current Density Component

  • Oh, Suk-Hoon;Park, Tae-Seok;Han, Jae-Yong;Lee, Soo-Yeol
    • Journal of Biomedical Engineering Research
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    • v.25 no.3
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    • pp.183-188
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    • 2004
  • Magnetic resonance current density imaging (MRCDI) is a useful method for measuring electrical current density distribution inside an object. To avoid object rotations during the conventional MRCDI scans, we have reconstructed current density component images by applying a spatial filter to the magnetic field data measured both inside and outside the object. To measure the magnetic field outside the object with MRI, we immersed the object in a water tank. To evaluate accuracy of the current density imaging, we have made a conductivity phantom with a corresponding finite element method model. We have compared the experimentally obtained current density images with the ones calculated by the finite element method. The average errors of the reconstructed current density images were 6.6 ∼ 45.4 % when the injected currents were 1 ∼ 24 mA. We expect that the current density component imaging technique can be used in diverse biomedical applications such as electrical therapy system developments and biological electrical safety analysis.

Measurements of Impervious Surfaces - per-pixel, sub-pixel, and object-oriented classification -

  • Kang, Min Jo;Mesev, Victor;Kim, Won Kyung
    • Korean Journal of Remote Sensing
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    • v.31 no.4
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    • pp.303-319
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    • 2015
  • The objectives of this paper are to measure surface imperviousness using three different classification methods: per-pixel, sub-pixel, and object-oriented classification. They are tested on high-spatial resolution QuickBird data at 2.4 meters (four spectral bands and three principal component bands) as well as a medium-spatial resolution Landsat TM image at 30 meters. To measure impervious surfaces, we selected 30 sample sites with different land uses and residential densities across image representing the city of Phoenix, Arizona, USA. For per-pixel an unsupervised classification is first conducted to provide prior knowledge on the possible candidate spectral classes, and then a supervised classification is performed using the maximum-likelihood rule. For sub-pixel classification, a Linear Spectral Mixture Analysis (LSMA) is used to disentangle land cover information from mixed pixels. For object-oriented classification several different sets of scale parameters and expert decision rules are implemented, including a nearest neighbor classifier. The results from these three methods show that the object-oriented approach (accuracy of 91%) provides more accurate results than those achieved by per-pixel algorithm (accuracy of 67% and 83% using Landsat TM and QuickBird, respectively). It is also clear that sub-pixel algorithm gives more accurate results (accuracy of 87%) in case of intensive and dense urban areas using medium-resolution imagery.

A Comprehensive Representation Model for Spatial Relations among Regions and Physical Objects considering Property of Container and Gravity (Container 성질과 중력을 고려한 공간과 객체의 통합적 공간관계 표현 모델)

  • Park, Jong-Hee;Lim, Young-Jae
    • Journal of KIISE:Software and Applications
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    • v.37 no.3
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    • pp.194-204
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    • 2010
  • A space, real or virtual, comprises regions as its parts and physical objects residing in them. A coherent and sophisticated representaion scheme for their spatial relations premises the precision and plausibility in its associated agents' inferencing on the spatial relations and the development of events occurring in such a space. The existing spatial models are not suitable for a comprehensive representation of the general spatial relations in that they have limited expressive powers based on the dichotomy between the large and small scales, or support only a small set of topological relations. The representaion model we propose has the following distinctive chracteristics: firstly, our model provides a comprehensive representation scheme to accommodate large and small scale spaces in an integrated fashion; secondly, our model greatly elaborated the spatial relations among the small-scale objects based on their contact relations and the compositional relations among their respective components objects beyond the basic topological relations like disjoint and touch; thirdly, our model further diversifies the types of supported relations by adding the container property besides the soildness together with considering the gravity direction. The resulting integrated spatial knowledge representation scheme considering the gravity allows the diverse spatial relations in the real world to be simulated in a precise manner in relation to the associated spatial events and provides an expression measure for the agents in such a cyber-world to capture the spatial knowledge to be used for recognizing the situations in the spatial aspects.

Feature Extraction Of Content-based image retrieval Using object Segmentation and HAQ algorithm (객체 분할과 HAQ 알고리즘을 이용한 내용 기반 영상 검색 특징 추출)

  • 김대일;홍종선;장혜경;김영호;강대성
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.453-456
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    • 2003
  • Compared with other features of the image, color features are less sensitive to noise and background complication. Besides, this adding to object segmentation has more accuracy of image retrieval. This paper presents object segmentation and HAQ(Histogram Analysis and Quantization) algorithm approach to extract features(the object information and the characteristic colors) of an image. The empirical results shows that this method presents exactly spatial and color information of an image as image retrieval's feature.

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A Multimedia Query Language for Object-Oriented Multimedia Databases (객체 지향 멀티미디어 데이타베이스를 위한 멀티미디어 질의어)

  • 노윤묵;이석호;김규철
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.5
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    • pp.671-682
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    • 1995
  • In this paper, we propose a multimedia query language MQL which defines and manipulates multimedia data as integration of monomedia data in time and space. The MQL is designed for a multimedia data model, called the object-relationship model, and based on the multimedia object calculus which formally describes operations on multimedia data. The SQL- like syntax for class definition and object manipulation, such as retrieval, insert, update, and delete, is defined. We show how the MQL can represent the user queries using composite temporal-spatial class structures and various relationships, such as equivalence and sequence.

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Object-Based Modeling and Language for an Object-Oriented Spatiao-Temporal Database System (객체지향 시공간 데이터베이스 시스템의 객체기반 설계 및 질의어)

  • Kim, Yang Hee
    • The Journal of Korean Association of Computer Education
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    • v.10 no.2
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    • pp.101-113
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    • 2007
  • In this paper, we present an object-based modeling and language for an object-oriented spatio-temporal database system. For handling the structure of spatio-temporal objects and the spatio-temporal operators, we propose the two layers of data modeling: a spatio-temporal object model (STOM) and an spatio_temporal internal description model (STIM). We then propose STOQL, a spatio-temporal object-oriented query language. STOQL provides an integrated mechanism for the graphical display of spatial objects and the retrieval of spatio-temporal and aspatial objects.

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