• Title/Summary/Keyword: 경계선 기법

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Utilizing Airborne LiDAR Data for Building Extraction and Superstructure Analysis for Modeling (항공 LiDAR 데이터를 이용한 건물추출과 상부구조물 특성분석 및 모델링)

  • Jung, Hyung-Sup;Lim, Sae-Bom;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.3
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    • pp.227-239
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    • 2008
  • Processing LiDAR (Light Detection And Ranging) data obtained from ALS (Airborne Laser Scanning) systems mainly involves organization and segmentation of the data for 3D object modeling and mapping purposes. The ALS systems are viable and becoming more mature technology in various applications. ALS technology requires complex integration of optics, opto-mechanics and electronics in the multi-sensor components, Le. data captured from GPS, INS and laser scanner. In this study, digital image processing techniques mainly were implemented to gray level coded image of the LiDAR data for building extraction and superstructures segmentation. One of the advantages to use gray level image is easy to apply various existing digital image processing algorithms. Gridding and quantization of the raw LiDAR data into limited gray level might introduce smoothing effect and loss of the detail information. However, smoothed surface data that are more suitable for surface patch segmentation and modeling could be obtained by the quantization of the height values. The building boundaries were precisely extracted by the robust edge detection operator and regularized with shape constraints. As for segmentation of the roof structures, basically region growing based and gap filling segmentation methods were implemented. The results present that various image processing methods are applicable to extract buildings and to segment surface patches of the superstructures on the roofs. Finally, conceptual methodology for extracting characteristic information to reconstruct roof shapes was proposed. Statistical and geometric properties were utilized to segment and model superstructures. The simulation results show that segmentation of the roof surface patches and modeling were possible with the proposed method.

Study for the Development of an Optimum Hull Form using SQP (SQP법을 이용한 최적선형개발에 대한 연구)

  • Choi, Hee-Jong;Lee, Gyoung-Woo;Yun, Soon-Dong
    • Journal of Navigation and Port Research
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    • v.30 no.10 s.116
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    • pp.869-875
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    • 2006
  • This paper presents the method for developing an optimum hull form with minimum wave resistance using SQP(sequential quadratic programming) as an optimization technique. The wave resistance is evaluated by a Rankine source panel method with non-linear free surface conditions and the ITTC 1957 friction line is used to predict the frictional resistance coefficient. The geometry of the hull surface is represented and modified using NURBS(Non-Uniform Rational B-Spline) surface patches. To verity the validity of the developed program the numerical calculations for Wigley hull and Series 60( $C_B=0.6$) hull have been performed and the results obtained by the numerical calculations have been compared with the original hulls.

Study for the Development of an Optimum Hull Form using SQP (SQP법을 이용한 최적선형개발에 대한 연구)

  • Choi, Hee-Jong;Lee, Gyoung-Woo;Kim, Sang-Hoon;Kim, Ho
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.47-53
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    • 2005
  • This paper presents the method for developing an optimum hull form with minimum wave resistance using SQP(sequential quadratic programming) as an optimization technique. The wave resistance is evaluated by a Rankine source panel method with non-linear free surface conditions and the ITTC 1957 friction line is used to predict the frictional resistance coefficient. The geometry of the hull surface is represented and modified using NURBS(Non-Uniform Rational B-Spline) surface patches. To verity the validity of the developed program the numerical calculations for Wigley hull and Series 60(C${_B}$=0.6) hull had been performed and the results obtained after the numerical calculations had been compared with the original hulls.

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3D Medical Image Segmentation Using Region-Growing Based Tracking (영역 확장 기반 추적을 이용한 3차원 의료 영상 분할 기법)

  • Ko S.;Yi J.;Lim J.;Ra J. B.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3 s.61
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    • pp.239-246
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    • 2000
  • In this paper. we propose a semi-automatic segmentation algorithm to extract organ in 3D medical data by using a manually segmentation result in a sing1e slice. Generally region glowing based tracking method consists of 3 steps object projection. seed extraction and boundary decision by region growing. But because the boundary between organs in medical data is vague, improper seeds make the boundary dig into the organ or extend to the false region. In the proposed algorithm seeds are carefully extracted to find suitable boundaries between organs after region growing. And the jagged boundary at low gradient region after region growing is corrected by post-processing using Fourier descriptor. Also two-path tracking make it possible to catch up newly appeared areas. The proposed algorithm provides satisfactory results in segmenting 1 mm distance kidneys from X-rav CT body image set of 82 slices.

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Detection of Pavement Region with Structural Patterns through Adaptive Multi-Seed Region Growing (적응적 다중 시드 영역 확장법을 이용한 구조적 패턴의 보도 영역 검출)

  • Weon, Sun-Hee;Joo, Sung-Il;Na, Hyeon-Suk;Choi, Hyung-Il
    • The KIPS Transactions:PartB
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    • v.19B no.4
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    • pp.209-220
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    • 2012
  • In this paper, we propose an adaptive pavement region detection method that is robust to changes of structural patterns in a natural scene. In order to segment out a pavement reliably, we propose two step approaches. We first detect the borderline of a pavement and separate out the candidate region of a pavement using VRays. The VRays are straight lines starting from a vanishing point. They split out the candidate region that includes the pavement in a radial shape. Once the candidate region is found, we next employ the adaptive multi-seed region growing(A-MSRG) method within the candidate region. The A-MSRG method segments out the pavement region very accurately by growing seed regions. The number of seed regions are to be determined adaptively depending on the encountered situation. We prove the effectiveness of our approach by comparing its performance against the performances of seed region growing(SRG) approach and multi-seed region growing(MSRG) approach in terms of the false detection rate.

Accuracy Improvement of Frame Interpolation Algorithm using Wedge-shaped Block Partitioning (비정방형 블록을 이용한 보간 프레임의 정확도 향상 기법)

  • Jeong, Jae Heon;Jung, Ho Sun;Sunwoo, Myung Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.5
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    • pp.85-91
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    • 2015
  • This paper presents a novel frame rate up-conversion (FRUC) algorithm. Existing algorithms, in general, employ rectangular blocks for motion estimation and arbitrary shape of an actual object region cannot be precisely represented. On the other hand, the proposed wedge-shaped block partitioning algorithm partitions a rectangular block into two wedge-shaped blocks using the texture information, which makes better approximation for an actual object region. The wedge-shaped block partitioning algorithm as well as the adaptive motion vector prediction algorithm is used to reliably estimate the actual motion. Experimental results show that the proposed FRUC algorithm is superior to existing algorithms up to 1.988dB in PSNR and 0.0167 in SSIM comparisons.

Robust Extraction of Facial Features under Illumination Variations (조명 변화에 견고한 얼굴 특징 추출)

  • Jung Sung-Tae
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.6 s.38
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    • pp.1-8
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    • 2005
  • Facial analysis is used in many applications like face recognition systems, human-computer interface through head movements or facial expressions, model based coding, or virtual reality. In all these applications a very precise extraction of facial feature points are necessary. In this paper we presents a method for automatic extraction of the facial features Points such as mouth corners, eye corners, eyebrow corners. First, face region is detected by AdaBoost-based object detection algorithm. Then a combination of three kinds of feature energy for facial features are computed; valley energy, intensity energy and edge energy. After feature area are detected by searching horizontal rectangles which has high feature energy. Finally, a corner detection algorithm is applied on the end region of each feature area. Because we integrate three feature energy and the suggested estimation method for valley energy and intensity energy are adaptive to the illumination change, the proposed feature extraction method is robust under various conditions.

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A Study for the Border line Extraction technique of City Spatial Building by LiDAR Data (LiDAR 데이터와 항공사진의 통합을 위한 사각 빌딩의 경계점 설정)

  • Yeon, Sang-Ho;Lee, Young-Wook
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.27-29
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    • 2007
  • The visual implementation of 3-dimensional national environment is focused by the requirement and importance in the fields such as, national development plan, telecommunication facility deployment plan, railway construction, construction engineering, spatial city development, safety and disaster prevention engineering. The currently used DEM system using contour lines, which embodies national geographic information based on the 2-D digital maps and facility information has limitation in implementation in reproducing the 3-D spatial city. Moreover, this method often neglects the altitude of the rail way infrastructure which has narrow width and long length. There it is needed to apply laser measurement technique in the spatial target object to obtain accuracy. Currently, the LiDAR data which combines the laser measurement skill and GPS has been introduced to obtain high resolution accuracy in the altitude measurement. In this paper, we first investigate the LiDAR based researches in advanced foreign countries, then we propose data a generation scheme and an algorithm for the optimal manage and synthesis of railway facility system in our 3-D spatial terrain information. For this object, LiDAR based height data transformed to DEM, and the realtime unification of the vector via digital image mapping and raster via exactness evaluation is transformed to make it possible to trace the model of generated 3-dimensional railway model with long distance for 3D tract model generation.

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A Study on Technique Vowing of Roads and Buildings for Spatial Information Management of Cyber Urban Area (가상도시의 공간정보관리를 위한 도로 및 건물의 시각화 기법의 연구)

  • 연상호
    • The Journal of the Korea Contents Association
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    • v.1 no.1
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    • pp.15-23
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    • 2001
  • It is difficult to figure out the specific contents of the buildings in the internet spatial area, since those data on the internet present only the location of buildings and the outlines of lands on which buildings are located, An experimental study for the view management of building information at internet urban spatial area was conducted on the Web-GIS based map using hyper map. With the building information on the 2-D map, modified from the previous numerical map and the regional building information and additional information, a new form of building through 3-D icons was shown on the internet spatial area. This study shows the Web-based building management system, which is designed to manage attribute data about hyper-linked buildings of 2.5-D icons and to reproduce visual building information by putting a variety of information into hyper-linked icons on the hyper map. This system not only complements the lack of consistency between real buildings and those on the map, but also provides users with more familiar urban space, so that everybody can utilize the building information as long as he has access to the internet.

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Automatic Detection of Highlights in Soccer videos based on analysis of scene structure (축구 동영상에서의 장면 구조 분석에 기반한 자동적인 하이라이트 장면 검출)

  • Park, Ki-Tae;Moon, Young-Shik
    • The KIPS Transactions:PartB
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    • v.14B no.1 s.111
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    • pp.1-4
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    • 2007
  • In this paper, we propose an efficient scheme for automatically detecting highlight scenes in soccer videos. Highlights are defined as shooting scenes and goal scenes. Through the analysis of soccer videos, we notice that most of highlight scenes are shown around the goal post area. It is also noticed that the TV camera zooms in a setter player or spectators after the highlight stones. Detection of highlight scenes for soccer videos consists of three steps. The first step is the extraction of the playing field using a statistical threshold. The second step is the detection of goal posts. In the final step, we detect a zooming of a soccer player or spectators by using connected component labeling of non-playing field. In order to evaluate the performance of our method, the precision and the recall are computed. Experimental results have shown the effectiveness of the proposed method, with 95.2% precision and 85.4% recall.