• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.91-94
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• 2019

스케치를 거쳐 생성되는 디지털 자료로 건축도면이나 제품 디자인시안 등은 수요가 많음에도 불구하고 디지털 도면 자동생성에 대한 영상처리는 아직 연구되지 않고 있다. 현행 필기인식에 대한 영상처리 연구는 주로 글자나 숫자에 국한되어 있어 본 연구에서는 선으로 이루어진 필기를 인식하여 도면이라는 이진영상의 특징을 이용해 특징점을 도출하고 디지털 도면을 생성하는 영상처리를 제안한다. 먼저 입력받은 아날로그 스캔이미지를 메디안블러링과 OSTU임계처리로 노이즈가 없는 이진영상으로 변환한 후 해리스코너검출기를 이용하여 특징점을 검출하고 좌표를 추출하고, 좌표값을 활용해 외곽선과 내부윤곽선까지 구현하여 디지털도면을 양산한다.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.31-39
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• 2007

As the availability of images from airborne digital camera with high resolution is expanded, a lot of concern are shown about the production of orthoimage and digital map. This study presents the method of updating digital map using orthoimage from airborne digital camera image. Images were georectified using GPS surveying data. For the generation of orthoimage, Lidar DEM was used. The absolute positional accuracy of orthoimage was evaluated using GPS surveying data. And that of the building layer of digital map was estimated using the existed digital map at the scale of 1:1,000. The absolute positional accuracy of orthoimage was as followed: RMSE in X and Y were ${\pm}0.076m$ and ${\pm}0.294m$. The RMSE of the building layer were ${\pm}0.250m$ and ${\pm}0.210m$ in X and Y directions, respectively. The RMSE of the digital map using orthoimage from Aerial Digital Camera image fell within allowable error range established by NGII. Consequently, updating digital map using orthoimage from Aerial Digital Camera image can be applied to various fields including the construction of the framework data and the GIS of local government.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.1
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• pp.41-50
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• 2020

The National Geographic Information Institute of Korea takes digital aerial photograph images every two years to make and modify/renew the digital map. The cameras for aerial photogrammetry to capture these digital aerial photographs are divided into frame types and line types. Computer vision analysis of aerial photograph images was only possible for frame type. Thus, in this study, Line type aerial photograph images was intended to generate geospatial information through computer vision analysis, and forest geospatial information was created as a method for the utilization of aerial picture images. As a result, geospatial information generated by computer vision analysis of line type aerial photograph images showed that RMSE of horizontal and vertical position errors was less than quadruple that of GSD. Forest geospatial information was generated using geospatial information generated by computer vision analysis. It was confirmed that extraction of the crown of tree and calculation of tree height are possible. Through this study, it is expected that utilization of aerial photograph images will be improved.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.1
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• pp.751-760
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• 2009

This research aims to develop the strategy and method to enhance the reliability of image matching results and improve the efficiency of the matching process by utilizing LIDAR data in the main image matching processes. In this work, we present the methods to utilize LIDAR data in the selection of matching entities, the search for the matched entities and the evaluation of the matching results. The proposed method has been applied to medium-resolution digital aerial images and LIDAR data acquired at the same time. The results have been analyzed in comparison with an existing method using a virtual horizontal surface rather than LIDAR DEM. This analysis indicates that the proposed method can show significantly more improved performance than the existing method. The results of this study can contribute to the improvement of the currently available commercial image matching software and the enhancement of the DEM derived from LIDAR data and matching results.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.1
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• pp.105-113
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• 2011

Since existing thematic maps have been made with medium- to low-resolution satellite images, they have several shortcomings including low positional accuracy and low precision of presented thematic information. Digital aerial photo image taken recently can express panchromatic and color bands as well as NIR (Near Infrared) bands which can be used in interpreting forest areas. High resolution images are also available, so it would be possible to conduct precision land cover classification. In this context, this paper implemented object-based land cover classification by using digital aerial photos with 0.12m GSD (Ground Sample Distance) resolution and IKONOS satellite images with 1m GSD resolution, both of which were taken on the same area, and also executed qualitative analysis with ortho images and existing land cover maps to check the possibility of object-based land cover classification using digital aerial photos and to present usability of digital aerial photos. Also, the accuracy of such classification was analyzed by generating TTA(Training and Test Area) masks and also analyzed their accuracy through comparison of classified areas using screen digitizing. The result showed that it was possible to make a land cover map with digital aerial photos, which allows more detailed classification compared to satellite images.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.298-301
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• 2010

최근 디지털센서가 부착된 항공촬영용 디지털 카메라를 이용하여 수치영상을 취득하는 항공사진측량 방식을 적용하고 있다. 본 연구에서는 지형도제작의 가능성을 분석하기 위하여 1/5,000수치지형도 제작에서 면형방식 디지털카메라인 ULTRA-CAM영상과 촬영당시에 획득된 GPS/INS의 외부표정자료로부터 Direct Georeferencing기법을 적용하여 1/5,000수치지형도(수정)제작에 충분한 정확도를 확보할 수 있었다.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.246-251
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• 2008

현재까지 우리나라 하천관리는 기존의 도면관리 및 현장조사를 통한 정보관리에서 벗어나 WAMIS, RIMGIS와 같은 물 관련 하천기본지리정보 시스템을 구축하여 사용되어 왔다. 하지만 기 구축된 시스템들은 선(線) 중심의 2차원 하천 공간자료로 관리되어 실무자 중심의 친환경적 하천관리업무 지원을 위한 자료로서 활용성이 부족한 실정이다. 본 연구에서는 면(面) 중심의 입체적인 3차원 하천공간정보 구현과 체계적인 하천관리 업무가 가능하도록 항공사진(아날로그, 디지털) 및 다양한 위성영상에 대한 해상도 비교를 통한 하천 적용여부 분석을 수행하였다. 하천 적용성 분석을 통해 가장 효과적으로 판단되는 디지털 항공사진을 이용하여 하천관리 및 활용방안을 모색함으로써 효율적인 하천관리방안을 제시하고자 한다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.141-147
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• 2011

This study analyzed the issues and its usefulness of drawing small-scale digital map by using the large-scale digital map which was producted with high-resolution digital aerial photograph which are commonly photographed in recent years. To this end, correlation analysis of the feature categories on the digital map was conducted, and this map was processed by inputting data, organizing, deleting, editing, and supervising feature categories according to the generalization process. As a result, 18 unnecessary feature codes were deleted, and the accuracy of 1/5,000 for the digital map was met. Although the size of the data and the number of feature categories increased, this was proven to be shown due to the excellent description of the digital aerial photograph. Accordingly, it was shown that drawing a small-scale digital map with the large-scale digital map by digital aerial photograph provided excellent description and high-quality information for digital map.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.197-200
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• 2007

항공사진 원데이터의 변형을 방지하고 효율적인 관리를 위해서는 자동독취를 통한 수치화 방안이 마련되어야 한다. 항공사진 판독업무에 있어서 기존 판독자만 밀착항공사진과 입체경을 통하여 건축물의 형태와 변화 여부를 판단하던 것을 모니터 상에서 누구나 건물의 변동사항을 볼 수 있도록 효율적인 판독시스템을 구축하여 판독의 신뢰도를 높여야 한다. 판독시스템 구축은 디지털 영상의 다양한 활용과 업무의 효율성 확보 및 대민서비스 향상 차원에서 이루어져야 할 것이다. 또한 현재 외국의 항측사들이 실제로 활용하고 있으며 조만간 국내에서도 도입 예정인 디지털항공카메라는 항공사진의 수치화 단계를 거치치 않고 직접 수치항공영상을 취득 할 수 있으므로 수치화 과정에서 발생하는 많은 오류들을 제거할 수 있음은 물론 판독시스템을 활용한 데이터의 직접처리가 가능해 시간적, 경제적으로 많은 장점들을 가지고 있다. 그러므로 디지털항공카메라의 도입에 대비한 개발현황과 활용도 등에 관한 사전 연구가 수행되어야 한다. 본 연구에서는 사용자가 직접 입체 판독 및 분석을 수행할 수 있는 플랫폼을 구비함으로서 오류를 최소화 할 수 있도록 편광 모니터(Z-Screen)를 사용하여 수행하였다. 또한 환경은 Microsoft Window OS 환경 상에서 구동될 수 있도록 개발함으로서 시스템의 범용적 사용을 위한 기초 환경을 제공하도록 제안하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.8
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• pp.104-108
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• 2006

There are range and azimuth direction resolution of synthetic aperture radar on the aircraft or satellite. Wide bandwidth chirp pulse generation technology is prerequisite for SAR image with fine resolution. There are two kinds of digital chirp pulse generation technology as arbitrary waveform generator(AWG) and direct digital synthesizer(DDS). In this paper, we design and implement a digital chirp pulse generator to generate 300MHz wide bandwidth linear FM chirp pulse for the fine resolution image with direct digital synthesizer. Implemented chirp pulse generator can be useful for the SAR sensors to make 50cm range resolution image.