• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.117-123
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• 2013

This study focuses on the determination of optimal photographing angle and overlapping ratio for automatic image stitching system using a non-metric camera module with motorized head. Photographing overlap was calculated considering the angle of view on different kinds of lenses and moving angle of motorized head per each option, and optimal photographing angle and overlapping ratio could be determined through the experimental result using the operating time, data volume and performance of image stitching. Through this experiment, we could find that it was effective to take a picture with $36^{\circ}$ of interval(33.82% of overlap) in vertical direction and $24^{\circ}$ or $30^{\circ}$ of interval(36.51% or 20.63% of overlap) in horizontal direction using 35mm lens for automatic image stitching system.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.145-154
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• 2014

The road network becomes more complex and extensive. Therefore, the inconveniences are caused in accordance with the time delay of the restoration of damaged roads, demands for excessive costs on information collection, and limitations on acquisition of damage information of the roads. Recently, road centric spatial information is gathered using mobile multi sensor system for road inventory. But expensive MMS(Mobile Mapping System) equipments require high maintenance costs from beginning and takes a lot of time in the data processing. So research is needed for continuous maintenance by collecting and displaying the damaged information on a digital map using low cost mobile camera system. In this research we aim to develop the techniques for mosaic with a regular ground sample distance using successive image from oblique camera on a vehicle. For doing this, mosaic image is generated by estimating the homography of high resolution oblique image, and the ground sample distance and appropriate overlap are analyzed using high resolution aerial oblique images which contain resolution target. Based on this we have proposed the appropriate overlap and exposure interval for mobile road inventory system.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.71-75
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• 2009

본 논문에서는 영상 제작에 사용되는 Animatronics를 이용한 산업화 방안에 대하여 CT(Culture technology)를 통한 산업화 방안에 관하여 논 하고자 한다. 본 연구를 통한 다양한 방법을 제시하고, 최고의 테크닉을 구사하고 집성되는 기술의 집합은 아니지만 단 한 가지, 영화를 위해 탄생하고, 영화만을 위해 사라지는 것이 아니라 효용가치가 높은 부분으로의 전개가 필요할 것이다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.424-427
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• 2007

스테레오 영상으로부터 3차원 구조를 복원하기 위해서는 깊이맵에 해당하는 시차맵을 생성해야 한다. 시차맵 생성을 위해서는 정합비용을 계산하고, 집성한 후에 시차를 계산하는 절차로 이루어진다. 본 논문에서는 스테레오 영상으로부터 빠르고 안정된 시차맵을 생성하기 위해서 후처리 과정으로 각 스캔라인에 대해서 분산을 이용하여 세그멘테이션을 한 후에 세그멘테이션 별로 평균을 내어 객체간의 구분을 명확히 한다. 조밀 시차맵을 생성하기 위해서는 시차 계산에 실패한 화소들에 대해서도 시차를 계산해야 하는데 본 논문에서는 간단하게 인접 화소의 값을 복사하는 방법으로 홀을 메우는 방법을 제안한다. 실제 환경에서의 다양한 스테레오 영상에 대한 실험 결과들은 제안된 시차맵 생성과 홀을 메우는 방법이 기존의 시차맵 생성 기법만큼 빠르고 기존의 방법보다 좀더 안정적이고 다양한 컴퓨터 비전 시스템응용에 적용될 수 있음을 보여준다.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.941-951
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• 2018

Utilization and demand of UAV (unmanned aerial vehicle) for the generation of 3D city model are increasing. In this study, we performed an experiment to adjustment position/orientation of UAV with incomplete attitude information and to extract point cloud data. In order to correct the attitude of the UAV, the rotation angle was calculated by using the continuous position information of UAV movements. Based on this, the corrected position/orientation information was obtained by applying IBA (Incremental Bundle Adjustment) based on photogrammetry. Each pair was transformed into an epipolar image, and the MDR (Multi-Dimensional Relaxation) technique was applied to obtain high precision DSM. Each extracted pair is aggregated and output in the form of a single point cloud or DSM. Using the DJI inspire1 and Phantom4 images, we can confirm that the point cloud can be extracted which expresses the railing of the building clearly. In the future, research will be conducted on improving the matching performance and establishing sensor models of oblique images. After that, we will continue the image processing technology for the generation of the 3D city model through the study of the extraction of 3D cloud It should be developed.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.103-114
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• 2013

In this study, we established the ortho mosaic imagery on the Korean Peninsula using KOMPSAT-2 images and conducted an accuracy assessment. Rational Polynomial Coefficient(RPC) modeling results were mostly less than 2 pixels except for mountainous regions which was difficult to select a Ground Control Point(GCP). Digital Elevation Model(DEM) which was made using the digital topographic map on the scale of 1:5,000 was used for generating an ortho image. In the case of inaccessible area, the Shuttle Radar Topography Mission(SRTM) DEM was used. Meanwhile, the ortho mosaic image of the Korean Peninsula was produced by each ortho image aggregation and color adjustment. An accuracy analysis for the mosaic image was conducted about a 1m color fusion image. In order to verify a geolocation accuracy, 813 check points which were acquired by field survey in South Korea were used. We found that the maximum error was not to exceed 5m(Root Mean Square Error : RMSE). On the other hand, in the case of inaccessible area, the extracted check points from a reference image were used for accuracy analysis. Approximately 69% of the image has a positional accuracy of less than 3m(RMSE). We found that the seam-line accuracy among neighboring image was very high through visual inspection. However, there were a discrepancy with 1 to 2 pixels at some mountainous regions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.485-492
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• 2012

Today, a digital airborne imaging sensor plays an important role in construction of the numerous National Spatial Data Infrastructure. However, an appropriate quality assesment procedure for the acquired digital images should be preceded to make them useful data with high precision and reliability. A lot of studies therefore have been conducted in attempt to assess quality of digital images at home and abroad. In this regard, many test fields have been already established and operated to calibrate digital photogrammetric airborne imaging systems in Europe and America. These test fields contain not only GCPs(Ground Control Points) to test geometric performance of a digital camera but also various types of targets to evaluate its spatial and radiometric resolution. The purpose of this paper is to present a method to verify the spatial resolution of the Intergraph DMC digital camera and its results based on an experimental field testing. In field test, a simple bar target to be easily identified in image is used to check the spatial resolution. Images, theoretically designed to 12cm GSD(Ground Sample Distance), were used to calculate the actual resolution for all sub-images and virtual images in flight direction as well as in cross flight direction. The results showed that the actual image resolution was about 0.6cm worse than theoretically expected resolution. In addition, the greatest difference of 1.5cm between them was found in the image of block edge.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.4
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• pp.343-350
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• 2006

For integrating and utilizing the statistical data, which is summarized by arbitrary areal unit such as demographics, with stellite imagery or other GIS data, areal unit of both data should be accorded. Dasymetric mapping is proposed as a useful method fur disaggregating the aggregated statistical data to finer areal unit or generating surface model from object data such as polygonal area. This research evaluate the effectiveness of dasymetric mapping by 1) summarizing the yellow page information by administrative district, 2) modeling the business density using dasymetric mapping, and 3) comparing the business densities of raw data and that of spatial interpolation result.