• Title/Summary/Keyword: 선분추출

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TIN based Matching using Stereo Airphoto and Airborne LiDAR (입체항공사진과 항공 LiDAR를 이용한 TIN 기반 정합)

  • Kim, Hyung-Tae;Han, Dong-Yeob
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.4
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    • pp.443-452
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    • 2008
  • To deduce 3D linear information which express shapes of buildings out of airphoto by fusion of airphoto and LiDAR data, this research went through 2 process. First, research made LiDAR data into projected data of 2D based on airphoto. For this, the virtual points were added to solve the visual problem of building boundary area which has poor information because the attribute in LiDAR data. Research construct irregular triangular nets from modified LiDAR data and judge visual triangular nets out of image. Through this, research can make reference to information of triangular nets in each image pixel. Second, 3D information was extracted from stereo images segments by combining extracted information of visible region and 2D irregular triangular nets. Matching way based on TIN for segments from stereo images was used. Matching condition based on TIN can improve about 20% of edge matching accuracy compared to existing quadrilateral condition of epipolar geometry.

Marker Recognition System for the User Interface of a Serious Case (중증환자 인터페이스를 위한 마커 인식 시스템)

  • So, In-Mi;Kang, Sun-Kyung;Kim, Young-Un;Jung, Sung-Tae
    • The KIPS Transactions:PartB
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    • v.14B no.3 s.113
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    • pp.191-198
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    • 2007
  • In this paper, we present a marker detection and recognition method from camera image for a disabled person to interact with a server system which can control appliance of surrounding environment. It converts the camera image to a binary image by using multi-threshold and extracts contours of objects in the binary image. After that, it approximates the contours to a list of line segments. It finds rectangular markers by using geometrical features which are extracted from the approximated line segments. It normalizes the shape of extracted markers into exact squares by using the warping technique. It extracts feature vectors from marker image by using principal component analysis and then recognizes the marker. The proposed marker recognition system is robust for light change by using multi-threshold. Also, it is robust for angular variation of camera by using warping technique and principal component analysis. Experimental results show that the proposed method achieves 100% recognition rate at maximum for 21 markers and execution speed of 12 frames/sec.

Development of a Detection and Recognition System for Rectangular Marker (사각형 마커 검출 및 인식 시스템 개발)

  • Kang Sun-Kyung;Lee Sang-Seol;Jung Sung-Tae
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.4 s.42
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    • pp.97-107
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    • 2006
  • In this paper, we present a method for the detection and recognition of rectangular markers from a camera image. It converts the camera image to a binary image and extracts contours of objects in the binary image. After that. it approximates the contours to a list of line segments. It finds rectangular markers by using geometrical features which are extracted from the approximated line segments. It normalizes the shape of extracted markers into exact squares by using the warping technique. It extracts feature vectors from marker image by using principal component analysis. It then calculates the distance between feature vector of input marker image and those of standard markers. Finally, it recognizes the marker by using minimum distance method. Experimental results show that the Proposed method achieves 98% recognition rate at maximum for 50 markers and execution speed of 11.1 frames/sec for images which contains eleven markers.

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Real-Time Road Lane Recognition for Autonomous Driving (자율 주행을 위한 실시간 차선 인식)

  • Hwang, In-Chan;Lee, Bong-Hwan;Lee, Kyu-Won
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.04a
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    • pp.94-97
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    • 2009
  • 본 논문에서는 실제 도로 환경에서의 실시간 차선 인식 방법을 제안한다. 전방주시카메라를 활용하여 촬영한 입력영상으로부터 도로영역에 해당하는 관심영역을 추출하고 반복적인 평균 명도를 측정하여 이진화함으로써 차선 특징을 검출하고 YCbCr 변환한 영상에 대한 실험 임계값을 적용하여 중앙선의 특징을 검출하였다. 이에 Canny 알고리즘을 이용한 에지 추출로 허프 변환시의 작업량을 최소화하였으며 허프 변환하여 얻은 차선 후보군으로부터 각도를 기반으로 필터링하여 통계적으로 우선순위가 높은 선분을 차선으로 인식하였다. 또한 실제 도로 환경에서 수집한 동영상으로 실험한 결과 강건한 차선 인식률을 보였다.

A Sequential Separation Procedure for the Determination of Uranium, Thorium and Their Isotopes in Geological Materials (지질시료 중의 U과 Th 분석 및 자연방사성동위원소 측정을 위한 화학적 분리)

  • Kim, Jung Suk;Choi, Kwang Soon
    • Analytical Science and Technology
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    • v.10 no.5
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    • pp.307-314
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    • 1997
  • Inductively coupled plasma atomic emission spectrometry(ICP/AES) was used for the determination of uranium and thorium in geological materials. Samples were predecomposed by mixed acid digestion technique. The separation of the uranium and thorium was achieved by systematic solvent extraction with TTA(thenoyltrifluoroacetone) and TOA (tri-n-octylamine) and back extraction into HCl. The results for standard rock sample, NIST SRM 278, showed a good agreement with those certified from NIST as well as found values by other non-destructive techniques. Additional purification for extracted portions was carried out by anion exchange chromatography for measurement of several natural radioisotopes of uranium and thorium by alpha spectrometry.

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A Study on the Asphalt Road Boundary Extraction Using Shadow Effect Removal (그림자영향 소거를 통한 아스팔트 도로 경계추출에 관한 연구)

  • Yun Kong-Hyun
    • Korean Journal of Remote Sensing
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    • v.22 no.2
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    • pp.123-129
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    • 2006
  • High-resolution aerial color image offers great possibilities for geometric and semantic information for spatial data generation. However, shadow casts by buildings and trees in high-density urban areas obscure much of the information in the image giving rise to potentially inaccurate classification and inexact feature extraction. Though many researches have been implemented for solving shadow casts, few studies have been carried out about the extraction of features hindered by shadows from aerial color images in urban areas. This paper presents a asphalt road boundary extraction technique that combines information from aerial color image and LIDAR (LIght Detection And Ranging) data. The following steps have been performed to remove shadow effects and to extract road boundary from the image. First, the shadow regions of the aerial color image are precisely located using LEAR DSM (Digital Surface Model) and solar positions. Second, shadow regions assumed as road are corrected by shadow path reconstruction algorithms. After that, asphalt road boundary extraction is implemented by segmentation and edge detection. Finally, asphalt road boundary lines are extracted as vector data by vectorization technique. The experimental results showed that this approach was effective and great potential advantages.

A Study on Game Character Classification Based on Texture and Edge Orientation Feature (질감 및 에지 방향 특징에 기반한 게임 캐릭터 분류에 관한 연구)

  • Park, Chang-Min
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.6
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    • pp.1318-1324
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    • 2012
  • This paper proposes a novel method for Game character classification based on texture and edge orientation feature. The character dose not move(NPC) and move the character is classified. Classification of property within the character of straight line segments are used to extract features. First, the character inside edge feature extraction and then calculates EEDH, SSPD. The extracted attribute represents the energy of a particular direction. Thus, these properties were used to classify of NPC and Monster. The proposed method, the user can reduce the unnecessary time in the game.

Height Estimation of the Flat-Rooftop Structures using Line-Based Stereo Matching (직선 기반 스테레오 정합을 이용한 평면 지붕 인공지물의 고도 정보 추출)

  • 최성한;엄기문;이쾌희
    • Korean Journal of Remote Sensing
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    • v.11 no.3
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    • pp.61-70
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    • 1995
  • In this paper, the algorithm to extract the height of flat-rooftop structures in stereo aerial image is suggested with an assumption that location, orientation, focal length, and field of view of a camera are known. It can be adapted to stereo aerial or satellite images. For performing feature-based stereo matching, the line segments suitable to describe the shape of general buildings are chosen as the feature. This paper is composed of three categories;the first step is to extract edges of structures with the polygon extraction algorithm which utilizes the edge following method, the second step is to perform the line segment matching with the camera information, and the last step is to calculate the location of each matched line and to estimate heights. The stereo images used in experiments are not real but synthetic ones. The experiment shows good results.

A High Precision Line Detection Based on Local Area CCT Method (국소영역 내의 CCT법을 이용한 고정밀 직선 검출)

  • Jung, Nam-Chae
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.2
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    • pp.82-89
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    • 2013
  • A detection method of high precision digital line within image is proposed in this paper. If we set the size of image to $N{\times}N$, in fact it is difficult to use the resulting values that the amount of computation is $O(N^4)$. Multiple algorithms are examined to reduced the amount of computation to $O(N^3)$, while suppressing the degradation of precision. How to detect line from the image processing, after stretching treatment of line segments extracted by Hough transform in the local area of an image is a great way to be able to detect several long or short line at high speed, but this method is slightly less precision in the detection of tilted line segments. In this paper, a line detection method improving the precision detection of tilted line segment is applied to the local area, thereby this method does not reduce the processing speed, while it is high precision method for detecting line segments. The experimental results confirm that the proposed method can detect a high precision line in a shorter period of time, compared with the existing methods.

Performance Enhancement of Marker Detection and Recognition using SVM and LDA (SVM과 LDA를 이용한 마커 검출 및 인식의 성능 향상)

  • Kang, Sun-Kyoung;So, In-Mi;Kim, Young-Un;Lee, Sang-Seol;Jung, Sung-Tae
    • Journal of Korea Multimedia Society
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    • v.10 no.7
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    • pp.923-933
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    • 2007
  • In this paper, we present a method for performance enhancement of the marker detection system by using SVM(Support Vector Machine) and LDA(Linear Discriminant Analysis). It converts the input image to a binary image and extracts contours of objects in the binary image. After that, it approximates the contours to a list of line segments. It finds quadrangle by using geometrical features which are extracted from the approximated line segments. It normalizes the shape of extracted quadrangle into exact squares by using the warping technique and scale transformation. It extracts feature vectors from the square image by using principal component analysis. It then checks if the square image is a marker image or a non-marker image by using a SVM classifier. After that, it computes feature vectors by using LDA for the extracted marker images. And it calculates the distance between feature vector of input marker image and those of standard markers. Finally, it recognizes the marker by using minimum distance method. Experimental results show that the proposed method achieves enhancement of recognition rate with smaller feature vectors by using LDA and it can decrease false detection errors by using SVM.

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