• Korean Journal of Remote Sensing
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• v.28 no.2
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• pp.191-202
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• 2012

A high resolution satellite imagery such as KOMPSAT-2 includes a material containing rational polynomial coefficient (RPC) for three-dimensional geopositioning. However, image geometries which are calculated from the RPC must have inevitable systematic errors. Thus, it is necessary to correct systematic errors of the RPC using several ground control points (GCPs). In this paper, we propose an efficient method for automatic correction of image geometries using tie points of a stereo pair and the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) without GCPs. This method includes four steps: 1) tie points extraction, 2) determination of the ground coordinates of the tie points, 3) refinement of the ground coordinates using SRTM DEM, and 4) RPC adjustment model parameter estimation. We validates the performance of the proposed method using KOMPSAT-2 stereo pair. The root mean square errors (RMSE) achieved from check points (CPs) were about 3.55 m, 9.70 m and 3.58 m in X, Y;and Z directions. This means that we can automatically correct the systematic error of RPC using SRTM DEM.

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.152-153
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• 2005

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.269-270
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• 2014

본 연구에서는 모션그래픽 응용으로 3D 공간감 연출에 대해서 제안하였다. 3D 공간에 입체적 효과를 연출하여 작품 전시회 효과를 나타내고, 다양한 공간 효과를 연출하여 2D의 평면 효과가아닌 3D 공간 효과를 연출함으로써 다양한 3D입체감 효과를 높여 방송, 다큐 같은 영상 전시에 응용할 수 있다고 제안한다.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.157-163
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• 2013

Purpose: This study was investigated weather watching 2D and 3D images effecting on accommodative function (AF), and differences between changes of AF by 2D and 3D. Methods: 50 subjects (male 30, female 20) aged 20's to 40's years old ($22.9{\pm}3.93$ years) who are available to watching 3D images were participated for this study. Accommodative amplitude (AA) by near point of accommodation (NPA), accommodative response (AR), positive and negative relative accommodation (PRA, NRA), accommodative facility (AF) were measured before, after watching 2D and 3D images at 1 m distance for 30 minutes respectively. Results: Accommodative amplitude after both watching 2D and 3D images decreased comparing to before watching images, and AA after watching 3D images was significantly lower than after watching 2D images. AR after both watching 2D and 3D images increased comparing to before watching images, but there was no difference between 2D and 3D. PRA and NRA were not significantly different between before, after watching 2D and 3D images. Accommodation speed by AF was increased for before watching ($13.52{\pm}3.32$ cpm) following by for after watching 2D images ($14.28{\pm}3.21$ cpm) and for watching 3D images ($14.90{\pm}3.27$ cpm). Conclusions: Watching images at close distance is effect to accommodation functions, and sequence of AA decrease of before watching images following by after watching 2D images and after watching 3D images may effect to asthenopia with same sequence as AA decrease. The results of increase of AF after watching images, specially 3D images show a possibility of vision therapy and further detail VT studies using 3D images are required in the future.

• Tunnel and Underground Space
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• v.17 no.2 s.67
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• pp.139-151
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• 2007

Stereophotogrammetry is a method to extract information of an interested area by constructing a stereo-image from two or more photos. In this study, the stereophotogrammetry was adopted to obtain the joint orientation and trace length from a sampling window and its measurements were compared with the result by a clinocompass and measuring tape to evaluate the applicability of the stereophotogrammetry to rock joint survey. A commercial stereophotogrammetry program, ShapeMetriX 3D, was used for this purpose. Firstly, the accuracy of the measuring method using ShpaeMetrix 3D was evaluated by a model test. Secondly, joint orientations on a rock slope and tunnel were obtained by using ShapeMetriX 3D and compared with the measurement by a clinocompass. Finally. the effect of base-depth ratio in photographing was evaluated by comparing images with various base-depth ratios, and the usefulness of closed-up photographing on a rock exposure to increase the measurement accuracy was tested. The dip and dip direction of each model plane obtained by ShapeMetriX 3D showed an error ranged between $-5^{\circ}\;and\; 5^{\circ}$ on the basis of the results by the measuring tape. Base-depth ratio proved not to influence the analysis result by ShapeMetriX 3D if all the images were taken without any hidden area. The close-up photographing turned out useful to obtain the detailed images and therefore precise result when ShapeMetriX 3D was adopted.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.29 no.12
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• pp.17-23
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• 2011

• Proceedings of the Korea Society for Simulation Conference
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• 2000.04a
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• pp.119-124
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• 2000

최근 다양한 분야에서 Virtual Reality(가상현실) 기술을 이용하여 개발 및 응용시스템 환경을 구축하고 있는 실정이다. 본 논문에서는 효과적인 입체 3-D 시각적인 인터페이스, 내비게이션(Navigation)과 주요설비(facilit) 조작 등을 통하여 효율적인 교육효과를 지원하는 사이버환경 구축에 관하여 서술한다. 이러한 환경구축의 목적은 학생들(발전소 운전원 및 신입생)에게 원자력발전소에 대한 적절한 지식과 기술을 제공하고, 이러한 액티비티들을 통하여 효과적인 경험 취득 및 지식습득에 도움을 주려하느데 있다. 본 논문은 영광1호기 원자력발전소를 대상으로 3D 입체영상을 구현하여 발전소 운전 중에 가보지 못하는 위험한 시설물 및 기기들을 사이버 환경에서 볼 수 있도록 도와주며, 인터넷 인증을 받고 들어온 사용자에게 시설물 및 주요설비를 web browser를 통하여 자습 및 복습할 수 있는 환경 구축에 관하여 서술한다.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.169-179
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• 2014

In this paper, we propose a DOF (Depth of Field) correction technique by determining the values of the internal parameters of a 3-D camera which consists of stereoscopic cameras of different optical properties. If there is any difference in the size or the depth range of focused objects in the left and right stereoscopic images, it could cause visual fatigue to human viewers. The object size of in the stereoscopic image is corrected by the LUT of zoom lenses, and the forward and backward DOF are corrected by the object distance. Then the F-numbers are determined to adjust the optical properties of the camera for DOF correction. By applying the proposed technique to a main-sub type 3-D camera using a GUI-based DOF simulator, the DOF of the camera is automatically corrected.

• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.215-226
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• 2014

The 3D technology has been spread slowly and the reason would be attributed to the fact that most commercialized 3D displays require 3D glasses. There have been various researches on human factors of glass type 3D display. In this study we measured and modeled crosstalk as well as 3D visual fatigue induced by mobile glassless 3D display. Crosstalk as well as visual fatigue varied depending on horizontal position of the 3D mobile display. Measured crosstalk was relative low around the center of the display and it increased at the side of the display. Similar results were found in the measurement of 3D visual fatigue and discomfort. These results imply that human factors should be considered in the process of design and evaluation of mobile 3D displays.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.2
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• pp.151-157
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• 1990

This paper presents a method for rapid wire frame drawing of the 3D objects represented by the CSG scheme. When the two CSG trees are combined into one, the intersection parts of the polygons constituting the object corresponds to each subtree are computed, and the boundary representation of the combined object is obtained according to the given combinational operator and stored in the root node. The boundary representation in the root node is used in the wireframe drawing of the object and later computation of boundary representation. Bezier surface is taken as one of the primitive object the scan-line algorithm is used, which subdivides each scan-line into the spans where no polygon is intersected, and renders each span with the CSG representation of the object.