• 제목/요약/키워드: Image Transformation

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위성원격탐사와 분류 및 회귀트리를 이용한 중랑천 유역의 불투수층 추정 (Impervious Surface Estimation of Jungnangcheon Basin Using Satellite Remote Sensing and Classification and Regression Tree)

  • 김수영;허준행;허준;김성훈
    • 대한토목학회논문집
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    • 제28권6D호
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    • pp.915-922
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    • 2008
  • 불투수층은 자연적인 침투를 허용하지 않는 인위적인 토지피복상태로, 도시화율을 추정하거나 도시의 환경변화 정도를 분석하기 위한 척도로 사용되어 왔다. 수문학적인 관점에서 불투수층은 단기 유출현상에 큰 영향을 끼치는 요소로 급속한 도시화로 인해 불투수층의 영향이 더욱 커짐에 따라 불투수층의 추정에 대한 필요성이 증가하고 있다. 따라서 본 연구에서는 불투수층을 추정하기 위해 중랑천 유역을 대상지역으로 선정하고, $30m{\times}30m$ 공간해상도의 Landsat-7 ETM+ 영상과 $1m{\times}1m$의 고해상도 위성영상을 구축하였으며 tasselled cap 변환과 식생지수(NDVI) 변환을 수행하여 다양한 예측변수를 고려하였다. 수집된 학습자료에 분류 및 회귀트리를 적용하여 불투수층 추정모델을 구성하였고, 이를 지도화하여 중랑천 유역의 불투수층을 나타냈다.

컴퓨터 비젼을 이용한 파이프 불량 검사시스템 개발 (Development of Pipe Fault Inspection System using Computer Vision)

  • 박찬호;양순용;안경관;오현옥;이병룡
    • 제어로봇시스템학회논문지
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    • 제9권10호
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    • pp.822-831
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    • 2003
  • A computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and the radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation is introduced for line detection. The dimension of inner and outer radius of pipe is calculated by the proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle, by which pipes with wrong end-shape can be classified and removed.

Video Segmentation and Key frame Extraction using Multi-resolution Analysis and Statistical Characteristic

  • Cho, Wan-Hyun;Park, Soon-Young;Park, Jong-Hyun
    • Communications for Statistical Applications and Methods
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    • 제10권2호
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    • pp.457-469
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    • 2003
  • In this paper, we have proposed the efficient algorithm that can segment the video scene change using a various statistical characteristics obtained from by applying the wavelet transformation for each frames. Our method firstly extracts the histogram features from low frequency subband of wavelet-transformed image and then uses these features to detect the abrupt scene change. Second, it extracts the edge information from applying the mesh method to the high frequency subband of transformed image. We quantify the extracted edge information as the values of variance characteristic of each pixel and use these values to detect the gradual scene change. And we have also proposed an algorithm how extract the proper key frame from segmented video scene. Experiment results show that the proposed method is both very efficient algorithm in segmenting video frames and also is to become the appropriate key frame extraction method.

고품질 컬러인쇄물의 색 교정 시스템 개발에 관한 연구 (A Study on the Color Proofing System Development for High Quality Color Prints)

  • 송경철;강상훈
    • 한국인쇄학회지
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    • 제22권2호
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    • pp.55-72
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    • 2004
  • The term color management system design, an ensemble of algorithm that provides a framework in which color information can be processed consistently throughout a digital imaging system. This is most commonly achieved through the use of special color transformation, known as device independent color transformation based on ICC device profiles. The purpose of this paper is to present some of the scientific principles of color management, and the original color management algorithms and solutions for digital soft color proofing system development.

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Rectification of Perspective Text Images on Rectangular Planes

  • Le, Huy Phat;Madhubalan, Kavitha;Lee, Guee-Sang
    • International Journal of Contents
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    • 제6권4호
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    • pp.1-7
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    • 2010
  • Natural images often contain useful information about the scene such as text or company logos placed on a rectangular shaped plane. The 2D images captured from such objects by a camera are often distorted, because of the effects of the perspective projection camera model. This distortion makes the acquisition of the text information difficult. In this study, we detect the rectangular object on which the text is written, then the image is restored by removing the perspective distortion. The Hough transform is used to detect the boundary lines of the rectangular object and a bilinear transformation is applied to restore the original image.

콘크리트내 철근위치검출을 위한 레이더화상처리기술 (Rader Image Processing for Locating of Reinforcing bars in Concrete)

  • 박석균
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.807-812
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    • 1999
  • Locating of reinforcing bars, in particular to know their accurate depths, is very important thing in radar inspection of concrete structures. By the way, a depth estimation of reinforcing bars in concrete structures by the radar is not easy because micorwave propagation velocity in test area is generally unknown. This problem can be solved by Generalized Hough transformation technique. Using this technique, the micorwave propagation velocity in test area can be detected from the radar image, which appear as hyperbolas conveying the velocity information in their shape. A developed speed-up technique for the computation of the Generalized Hough transformation is also investigated in this study. As a result, although it becomes difficult to locate reinforcing bars when multiple parallel bars lying too close together, there is a possibility of detecting accurate depths of reinforcing bars in test area by the proposed method.

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일반화 Hough변환을 응용한 콘크리트 레이더 화상 내 실제 철근위치의 검출 해석 (Locating Reinforcing Bars in Concrete Structures Using Generalized Hough Transform of Radar Image)

  • 박석균
    • 콘크리트학회논문집
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    • 제12권1호
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    • pp.23-31
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    • 2000
  • Locating reinforcing bars, in particular to know their accurate depths, is very important in radar inspection of concrete structures. By the way, an accurate depth estimation of reinforcing bars in concrete structures by the radar is not easy because the microwave propagation velocity in test area is generally unknown. This problem can be solved by generalized Hough transformation technique. Using this technique, the microwave propagation velocity in test area can be detected from the radar image, which appear as hyperbolas conveying the velocity information in their shape. A developed speed-up technique for the computation of the Generalized Hough transformation is also investigated in this study. As a result, although it becomes difficult to locate reinforcing bars when multiple parallel bars lying too close together, there is a possibility of detecting accurate depths of reinforcing bars in test area by the proposed method

Development of Pipe-Inspection System Using Computer Vision

  • Park, Chan-ho;Lee, Byungryoung;Soonyoung Yang;Kyungkwan Ahn;Hyunog Oh
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.99.1-99
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    • 2002
  • In this paper, a computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplacian operator with input image which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along t...

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컴퓨터 비젼을 이용한 파이프 형상 검사시스템에 관한 연구 (A Study about Pipe Shape Inspection System for Computer Vision)

  • 김형석;이병룡;양순용;안경관;오현옥
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.946-950
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    • 2003
  • In this paper, a computer-vision based pipe shape inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle. by which pipes with wrong end-shape can be classified removed.

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새로운 선형의 외형적 카메라 보정 기법 (A New Linear Explicit Camera Calibration Method)

  • 도용태
    • 센서학회지
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    • 제23권1호
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    • pp.66-71
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    • 2014
  • Vision is the most important sensing capability for both men and sensory smart machines, such as intelligent robots. Sensed real 3D world and its 2D camera image can be related mathematically by a process called camera calibration. In this paper, we present a novel linear solution of camera calibration. Unlike most existing linear calibration methods, the proposed technique of this paper can identify camera parameters explicitly. Through the step-by-step procedure of the proposed method, the real physical elements of the perspective projection transformation matrix between 3D points and the corresponding 2D image points can be identified. This explicit solution will be useful for many practical 3D sensing applications including robotics. We verified the proposed method by using various cameras of different conditions.