• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3047-3049
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• 2000

The ability to efficiently and robustly recover accurate 3D terrain models from sets of stereoscopic images is important to many civilian and military applications. To develop an effective and practical terrain modeling system. We propose the methods which detect unreliable elevations in digital elevation maps (DEMs). and fuse several DEMs from multiple sources into an accurate and reliable result. This paper focuses on two key factors for generating robust 3D terrain models. the ability to detect unreliable elevation estimates. and to fuse the reliable elevations into a single optimal terrain model. We apply the correlation score methodology to reconstruct accurate DEM for multi-image and show the method is more effective than the conventional averaging method. The photo-realistic simulator is used for generating four simulated images from ground truth DEM and orthoimage.

• Journal of the Korean Geophysical Society
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• v.8 no.1
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• pp.23-33
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• 2005

The digital surface model (DSM) is used for several purposes in photogrammetry, remote sensing and laser scanned data such as orthoimage production, contours erivation, extraction of height information. Creation of a surface model from point-clouds (3-D sparse points) that can be derived from stereo imagery and range data (e.g. laser scanned data) can be done with several mathematical interpolation models. In this paper, thin-plate-spline (TPS) is used for digital surface modeling. Determination of suitable weight is an important problem in thin-plate function for a surface. The Voronoi algorithm has been proposed as a method for determination of the weight in thin-plate-spline. In this paper, methods has been tested for different surfaces. The results show that thin-plate-spline can be independent of weight.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.225-228
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• 2001

가상현실에서 사용되는 3 차원 디스플레이 방법은 크게 HMD 와 HTD 시스템으로 구분되어 연구/개발이 되고 있다. 그 중 HTD 시스템의 경우에는 일반적으로 Stereoscopic 디스플레이 방법과 흡사하다고 할 수 있다. 그러나, 그 적용면에 있어서 CRT 상의 적용은 사용자의 Perspective View 가 디스플레이 평면과 수평/수직인 것이 따라 발생하는 뒤틀림 현상과 한 사람의 사용자를 기반으로 생성된다는 점이다. 본 논문에서는 CRT 상에서 HTD 를 효율적으로 사용하기 위한 방안으로 한 사람의 사용자를 기반으로 하는 분자구조의 모델을 스테레오 HTD 시스템에 적용하여 보았다. 더불어 과학적인 데이터의 경우에 VRML 파일을 적용하였을 때의 효율성에 대하여 연구를 하였다.

• Korean Journal of Remote Sensing
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• v.17 no.2
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• pp.121-129
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• 2001

A DEM(digital elevation model) is generated from a SPOT panchromatic stereo-pair using automated algorithms over a 8 km$\times$10 km region around Mokpo city. The aims are to continue the accuracy assessment over diverse conditions and to examine the applicability of a SPOT DEM for coastal disaster monitoring. The accuracy is assessed with respect to three reference data sets: 10 global positioning system records, 19 leveling data, and 1:50,000 topography map. The planimetric error is 10.6m r.m.s. and the elevation erroer ranges from 12.4m to 14.4m r.m.s.. The DEM accuracy of the flat Mokpo region is consistent with that over a mountainous area, which supports the robustness of the algorithms. It was found that coordinate transformation errors are significant at a few meters when using the data from leveling and topographic maps. The error budget is greater than the requirements for coastal disaster monitoring. Exploiting that a sub-scene is used, the affine transformation improves the accuracy by 50% during the camera modeling.

• Journal of Sensor Science and Technology
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• v.7 no.6
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• pp.418-425
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• 1998

Stereo cameras are the most widely used sensing systems for automated machines including robots to interact with their three-dimensional(3D) working environments. The position of a target point in the 3D world coordinates can be measured by the use of stereo cameras and the camera calibration is an important preliminary step for the task. Existing camera calibration techniques can be classified into two large categories - linear and nonlinear techniques. While linear techniques are simple but somewhat inaccurate, the nonlinear ones require a modeling process to compensate for the lens distortion and a rather complicated procedure to solve the nonlinear equations. In this paper, a method employing a neural network for the calibration problem is described for tackling the problems arisen when existing techniques are applied and the results are reported. Particularly, it is shown experimentally that by utilizing the function approximation capability of multi-layer neural networks trained by the back-propagation(BP) algorithm to learn the error pattern of a linear technique, the measurement accuracy can be simply and efficiently increased.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.37 no.4
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• pp.37-45
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• 2000

In this paper we suggest a method of detecting the two eyes position of moving viewer by using images obtained through a color CCD camera, and also a method of rendering view-dependent 3D image which consists of depth estimation, image-based 3D object modeling and stereoscopic display process. Through the experiment of applying the suggested methods, we could find the accurate two-eyes position with the success rate of 97.5% within the processing time of 0.39 second using personal computer, and display the view-dependent 3D image using Fl6 flight model. And through the similarity measurement of stereo image rendered at z-buffer by Open Inventor and captured by stereo camera using robot, we could find that view-dependent 3D picture obtained by our proposed method is optimal to viewer.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.2 s.36
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• pp.3-13
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• 2006

Extraction of man-made objects from high resolution satellite images has been studied by many researchers. In order to reconstruct accurate 3D building structures most of previous approaches assumed 3D information obtained by stereo analysis. For this, they need the process of sensor modeling, etc. We argue that a single image itself contains many clues of 3D information. The algorithm we propose projects virtual shadow on the image. When the shadow matches against the actual shadow, the height of a building can be determined. If the height of a building is determined, the algorithm draws vertical lines of sides of the building onto the building in the image. Then the roof boundary moves along vertical lines and the footprint of the building is extracted. The algorithm proposed can use the shadow cast onto the ground surface and onto facades of another building. This study compared the building heights determined by the algorithm proposed and those calculated by stereo analysis. As the results of verification, root mean square errors of building heights were about 1.5m.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.4
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• pp.15-20
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• 2010

The three dimensional information is extracted and visualized using by stereo images of the object and the method for a 3D stereoscopic image is presented by the vergence control algorithm. The matching, which is applied a undistortion of lens and the energy function, is executed for the efficient extraction three dimensional information. Especially, applying the optimized method of matched line to the multi direction of the disparity imges. The disadvantages of multi directional method and reliability expansion method is collected. The matched interesting range of the three dimensional information is visualized using by VRML and more 3D stereoscopic image is visualized through the vergence control according to distance of the object. more improved three dimensional information is provided to observer by visualizing both of them at the same time.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.7
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• pp.104-115
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• 1999

This paper proposes an efficient method for 3D modeling of a human face from trinocular images by reconstructing face surface using range data. By using a trinocular camera system, we mitigated the tradeoff between the occlusion problem and the range resolution limitation which is the critical limitation in binocular camera system. We also propose an MPC_MBS (Matching Pixel Count Multiple Baseline Stereo) area-based matching method to reduce boundary overreach phenomenon and to improve both of accuracy and precision in matching. In this method, the computing time can be reduced significantly by removing the redundancies. In the model generation sub-pixel accurate surface data are achieved by 2D interpolation of disparity values, and are sampled to make regular triangular meshes. The data size of the triangular mesh model can be controlled by merging the vertices that lie on the same plane within user defined error threshold.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.1
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• pp.61-69
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• 2003

There is various kinds cause that influence to created DEM and orthoimage using stereo satellite images. Specialty, research about effect that GCP number gives to accuracy of DEM, orthoimage and modeling may have to be gone ahead. Therefore, this research increases GCP number by 5 to 30 and created each modeling, DEM and orthoimage using SPOT panchromatic images that resolution is 10m by digital image processing method. Accuracy assessment did by orthoimage using 20 check point. As a result, GCP number between 10∼30 modeling RMSE is 1 pixel low appear. Horizontal·vertical error that use orthoimage looked tendency that decrease GCP number increases, and confirmed by the most economical in GCP number 10∼15. Also, analyze correlation of GCP number and orthoimage position accuracy and presented improvement plan and research task hereafter.