• Title, Summary, Keyword: perspective projection

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An Efficient Perspective Projection using $\textrm{VolumePro}^{TM}$ Hardware (볼륨프로 하드웨어를 이용한 효율적인 투시투영 방법)

  • 임석현;신병석
    • Journal of KIISE:Computer Systems and Theory
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    • v.31 no.3_4
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    • pp.195-203
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    • 2004
  • VolumePro is a real-time volume rendering hardware for consumer PCs. However it cannot be used for the applications requiring perspective projection such as virtual endoscopy since it provides only orthographic projection. Several methods have been presented to approximate perspective projection by decomposing a volume into slabs and applying successive parallel projection to thou. But it takes a lot of time since the entire region of every slab should be processed, which does not contribute to final image. In this paper, we propose an efficient perspective projection method that makes the use of several sub-volumes with cropping feature of VolumePro. It reduces the rendering time in comparison to slab-based method without image quality deterioration since it processes only the parts contained in the view frustum.

Realtime Implementation Method for Perspective Distortion Correction (원근 왜곡 보정의 실시간 구현 방법)

  • Lee, Dong-Seok;Kim, Nam-Gyu;Kwon, Soon-Kak
    • Journal of Korea Multimedia Society
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    • v.20 no.4
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    • pp.606-613
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    • 2017
  • When the planar area is captured by the depth camera, the shape of the plane in the captured image has perspective projection distortion according to the position of the camera. We can correct the distorted image by the depth information in the plane in the captured area. Previous depth information based perspective distortion correction methods fail to satisfy the real-time property due to a large amount of computation. In this paper, we propose the method of applying the conversion table selectively by measuring the motion of the plane and performing the correction process by parallel processing for correcting perspective projection distortion. By appling the proposed method, the system for correcting perspective projection distortion correct the distorted image, whose resolution is 640x480, as 22.52ms per frame, so the proposed system satisfies the real-time property.

A Study on Shape from Patterns (3차원 물체의 형상 인식에 관한 연구)

  • Kim, Do-Nyun;Cho, Dong-Sub
    • Proceedings of the KIEE Conference
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    • pp.542-545
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    • 1990
  • Texture provides an important source of information about the local orientation of visible surfaces. In this study the 3D shape of a textured surface is recovered from its perspective projection image on the assumption that the texture is homogeneously distributed. To recover 3D structure, the distorting effects of the perspective projection must be distinguished from properties of the texture. In this study, paraperspective projection, approximation of perspective projection, has employed.

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A Rectification of Stereo Pairs Using Perspective Projection Matrices Estimated (추정된 원근투영행렬을 이용한 스테레오 영상 평행화에 관한 연구)

  • 정효림;이종수
    • Proceedings of the IEEK Conference
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    • pp.125-128
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    • 2002
  • This paper propose a rectification technique by applying the Projection matrices derived from perspective projection matrices estimated from self-calibrated stereo image pairs. The derivation is made such that two epipolar lines are in parallel. Rectified images are generated by reprojecting corresponding image points. For the performance analysis of this technique, vertical coordinates of rectified points are compare to those obtained by the technique[3].

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The Effectiveness of the Hemi-sphere Projection Method in the Analysis of Streetscape (가로경관 분석에서의 반구투영법의 효용성 검토)

  • 이인성;서정한
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.2
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    • pp.58-69
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    • 2003
  • The Hemi-sphere projection method produces an image that includes all surrounding visual landscape from a view point. This characteristic can solve the problem of perspective method that has only a limited view angle, and thus can be a potentially effective method for the analysis of visual landscape. This study tried to adopt the hemi-sphere projection method in the evaluation of streetscape, and examined its effectiveness and possibilities. Computer animations using the perspective method and the hemi-sphere method were produced for Bang-Hak Ro, Seoul, and the kames of the animations were reclassed to identify the visibility ratio of physical elements(buildings, sky and mountains). A preference questionnaire was given to 51 university students, and the relationships between the visibility ratio and visual preference were analyzed. The results showed that visual preference of streetscape can be explained by three factors: Openness, Uniformity, and Variousness, accounting for 63.2% of the total variance, and among which Openness showed the highest proportion at 32.1%. The visibility ratio calculated by the hemi-sphere method yielded strong correlation coefficients with Openness, and it was much higher than with the perspective method. The hemi-sphere method also produced significant correlation coefficients about Uniformity and Variousness, but the perspective method could not. The results demonstrated that the hemi-sphere method can provide more accurate observation of visual changes, and that it can be an effective method for the analysis of streetscape.

Real-time Harbor Monitoring System using HD-CCDV

  • Jang, Seon-Bong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.161-163
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    • 2011
  • 최근 몇 년사이 CCTV에 대한 활용도와 중요성이 대두되고 있으며, CCTV의 해상도 또한 SD급 CCTV에서 HD급 CCTV로 대부분 전환되고 있는 상황이다. HD급 CCTV는 고화질, 고해상도를 제공하는 장점을 갖지만, 많은 데이터 량으로 인해 실시간 처리가 어려운 문제점 또한 포함하고 있다. 또한 CCTV는 지능형 CCTV로의 기술적인 진보를 거듭하고 있으며, 대표적인 solution으로 증강현실(AR:Augmented Reality)을 꼽을 수 있다. 본 논문에서는 HD-CCTV의 최대 장점이라고 할 수 있는 실시간 영상에 선박의 정보(AIS : Automatic Identification System)을 결합하여 실시간으로 항만을 모니터링 하는 시스템을 구현하였다. 또한 750mm Zoom Lens를 탑재한 PanTilt 장비를 이용하여 선박을 targeting 하는 시스템 또한 구현하였다. 증강현실을 이용하여 실시간 영상과 선박 정보를 결합하였으며, 이를 구현하기 위해 perspective projection 방법을 통해 3차원 공간좌표계를 2차원으로 투영하였다. 실시간 처리를 위해 입력영상을 Block으로 분할하여 목적 좌표를 검색하였으며, 선박정보의 부드러운 이동을 위해 Dead Reckon 기법과 linear prediction 방법을 이용하여 선박 위치를 예측하였다. 마지막으로 삼각측량법에 기반하여 현재 PanTilt 장비를 목적된 장소로 이동시키는 시스템을 구현하였다.

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Multiview Autostereoscopic Display Technology and Applications

  • Kim, Sung-Sik;Shestak, Sergei A.
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.463-467
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    • 2003
  • Optical architecture and experimental results on low cost multiview autostereoscopic projection display are presented. The display, containing only one high resolution projection panel and only one projection lens is capable of displaying multiview autostereoscopic images. Key components, applied in the display are segmented mirror for splitting the projection beam and one-dimensional diffuser with slanted axis of diffusion for viewing zone formation. Image distortions, inherent in the display have been compensated with opposite sign pre-distortion of projected perspective images.

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Development of a Three Dimensional Mesh Generation Program for CFD Simulations (CFD 해석을 위한 3차원 격자생성 프로그램의 개발)

  • Chang J.;Kim S.-R.;Hur N.
    • 한국전산유체공학회:학술대회논문집
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    • pp.157-163
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    • 2001
  • In the present study a mesh generation program is developed for three dimensional flow analyses with complex geometry. By the present program one can define vertices using various coordinate systems and cells for finite volume approach. Rendered display of the generated mesh can be also available in both orthographic and perspective projection modes. Through perspective projection mode, one can check the quality of generated mesh by moving around inside the mesh like a virtual reality. The examples of the program execution is given in the paper.

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3D Surface Model Generation of Micro Structure by Self Calibration of The SEM Image (SEM 영상의 자체검정에 의한 미세구조물의 3차원 표면모델 생성)

  • 이효성;박형동
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • pp.151-159
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    • 2003
  • This study presents method for self-calibration of the SEM(Scanning Electron Microscope) stereo image using the standard microprobe with same grid pattern and using parallel and central perspective projection equation. Result showed that parallel projection method is more suitable for standard microprobe. The maximum error of 3D coordinates acquired by this method did not exceed 5 $\mu\textrm{m}$, and DSM(Digital Surface Model) for three dimensional measurement of the rock sample was generated by the digital photogrammetry. This result can be used for quantification of micro scale change of shape and analysis of the micro morphology of rock due to weathering.

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A Study of Mathematically Gifted Middle School Students' of Mathematical Thinking and the Teacher's Role in Teaching and Learning about the Central Projection and Perspective Drawing (중심사영과 투시도의 작도 학습에서 나타나는 중학교 수학영재들의 수학적 사고특성과 교사의 역할)

  • Lew, Hee Chan;Kang, Kyung Min
    • School Mathematics
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    • v.15 no.4
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    • pp.921-940
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    • 2013
  • This study is to analyze mathematically gifted middle school students' characteristics of mathematical thinking and the teacher's role in teaching and learning about the central projection and perspective drawing. And it will help to develop teaching and learning materials for the mathematically gifted. The result of this study is as followings : mathematically gifted middle school students show the various characteristics of mathematical thinking like as intuitive insight, generalization, logical thinking & mathematical abstraction and so on, and the teacher plays roles as instructional designer, facilitator, technical assistant and counselor.

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