• Korean Journal of Remote Sensing
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• v.6 no.1
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• pp.1-9
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• 1990

This paper presents a method of the constructing DEM(Digital Elevation Model) from the image data acquired from a commercial map using the scanner. Data acquistion, mark elimination, linking the broken line, elevation interpolation and 3D display processing are performed and the results are satisfatory.

• Journal of the Korean GEO-environmental Society
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• v.17 no.8
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• pp.39-44
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• 2016

Ground deformation around construction site in urban area where typically adjacent structures are located needs to be strictly controlled. Accordingly, it is very important to precisely monitor the ground deformation. Settlement beacon is typically employed to measure the ground deformation, but meanwhile the rapid development in electronic technology enables 3D image scanner to become available for measuring the ground deformation profile in usual construction sites. With respect to the profile measurement, the 3D scanner has an advantage, whereas its accuracy is somewhat limited because it does not measure the displacement directly. In this paper, we developed a conditional merging technique to combine the ground displacement measured from settlement beacon and the profile measured by the 3D scanner. Synthetic ground deformation profile was generated to validate the proposed technique. It is found that the ground deformation measurement error can be reduced significantly via the conditional merging technique.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.4
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• pp.399-404
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• 2002

In this study, it was intended to present solution for learners to understand and utilize photogrammetry more easily using economic medium except expensive measuring equipment. For this, 3D point data was analysed by generating event to stereo image on monitor, and input to CAD system automatically. so, real time vector editing and drawing with coordinates measurement were possible. The system was verified, and the monitoring for real construction was performed. so, it is expected to be utilized as a practical use software in related fields.

• Journal of KIBIM
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• v.5 no.4
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• pp.23-29
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• 2015

The purpose of this study is to provide considerations for developing reverse engineering guidelines for AEC(Architecture, Engineering and Construction). The reverse engineering is a methodology which has the purpose of extracting and recognizing geometries and properties from physical objects such as buildings, facilities, terrain and infrastructure including roads, bridges, and tunnels. To handle them for the purpose of construction management, maintenance, and operation, we should know the exact position, orientation, and dimension of the objects including their properties. As the viewpoint of the information extraction from reverse engineering, it is necessary to derive consideration factors for developing reverse engineering guidelines.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.4
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• pp.277-285
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• 2004

We present a new hybrid stereo matching technique in terms of the co-operation of area-based stereo and feature-based stereo. The core of our technique is that feature matching is carried out by the reference of the disparity evaluated by area-based stereo. Since the reference of the disparity can significantly reduce the number of feature matching combinations, feature matching error can be drastically minimized. One requirement of the disparity to be referenced is that it should be reliable to be used in feature matching. To measure the reliability of the disparity, in this paper, we employ the self-consistency of the disunity Our suggested technique is applied to the detection of 3D line segments by 2D line matching using our hybrid stereo matching, which can be efficiently utilized in the generation of the rooftop model from urban imagery. We carry out the experiments on our hybrid stereo matching scheme. We generate synthetic images by photo-realistic simulation on Avenches data set of Ascona aerial images. Experimental results indicate that the extracted 3D line segments have an average error of 0.5m and verify our proposed scheme. In order to apply our method to the generation of 3D model in urban imagery, we carry out Preliminary experiments for rooftop generation. Since occlusions are occurred around the outlines of buildings, we experimentally suggested multi-image hybrid stereo system, based on the fusion of 3D line segments. In terms of the simple domain-specific 3D grouping scheme, we notice that an accurate 3D rooftop model can be generated. In this context, we expect that an extended 3D grouping scheme using our hybrid technique can be efficiently applied to the construction of 3D models with more general types of building rooftops.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.1 s.28
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• pp.63-68
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• 2004

Since 20th century, the rapid growth in economy development and ill-advisable construction of infrastructure which causing injury of nature has generated an El Nino phenomenon problems. For this reason, establishment of heritage preservation plan is being required to prevent damages of important cultural assets from natural disaster. In this study, we obtained both 3D-dxf and VRML-wrl(which support 3D image) files from stone pagodas(stone cultural heritages) by using the digital photogrammetric program. Then database are formed by these two files with other attribute informations. And we made existing cultural heritages management information data format to be unified using JAVA, HTML, and Cosmo Player. Thus, we could construct the web-server for Cultural Heritages Management Information System to contribute not only effective management but also ease of use for expert or amateur user in using of cultural assets informations. And, in virtual reality system, we could make texture presented like as actual texture by using the VRML program.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.49-62
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• 2022

Borehole Data is geotechnical information provided so that workers can safely perform construction at the field. It creates 3D data and supports viewing as a 3D image. Currently, all Korean companies that develop programs using 3D visualization use the MVS program developed by C Tech Development Corporation. However, the MVS program is a commercial program, and it is difficult to use MVS in 3D related programs developed by Korean Companies. In this paper, we propose to develop a program that can replace MVS to generate a 3D stratum model from clustered borehole information using Python's Gempy open-source. The 3D stratum model program can creates point data for each stratum and can creates a surface for each stratum through interpolation. Then, the 3D stratum model program is completed by merging the surfaces of each stratum. It was confirmed that there was no difference when a 3D model was created and compared with the MVS program and the proposed program from the borehole data of a Goyang area.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.1
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• pp.19-30
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• 2007

Modeling 3D buildings is an essential process to revive the real world into a computer. There are two ways to create a 3D building model. The first method is to use the building layer of 1:1000 digital maps based on high density point data gained from airborne laser surveying. The second method is to use LiDAR point data with digital images achieved with LiDAR. In this research we tested one sheet area of 1:1000 digital map with both methods to process a 3D building model. We have developed a process, analyzed quantitatively and evaluated the efficiency, accuracy, and reality. The resulted differed depending on the buildings shape. The first method was effective on simple buildings, and the second method was effective on complicated buildings. Also, we evaluated the accuracy of the produced model. Comparing the 3D building based on LiDAR data and digital image with digital maps, the horizontal accuracy was within ${\pm}50cm$. From the above we derived a conclusion that 3D building modeling is more effective when it is based on LiDAR data and digital maps. Using produced 3D building modeling data, we will be utilized as digital contents in various fields like 3D GIS, U-City, telematics, navigation, virtual reality and games etc.

• Korean Journal of Artificial Intelligence
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• v.9 no.2
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• pp.7-14
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• 2021

Purpose: To solve urban problems, empirical research is being actively conducted to implement a smart city based on various ICT technologies, and digital twin technology is needed to effectively implement a smart city. A digital twin is essential for the realization of a smart city. A digital twin is a virtual environment that intuitively visualizes multidimensional data in the real world based on 3D. Digital twin is implemented on the premise of the convergence of GIS and BIM, and in particular, a lot of time is invested in data pre-processing and labeling in the data construction process. In digital twin, data quality is prioritized for consistency with reality, but there is a limit to data inspection with the naked eye. Therefore, in order to improve the required time and quality of digital twin construction, it was attempted to detect a building using Mask R-CNN, a deep learning-based masking algorithm for aerial images. If the results of this study are advanced and used to build digital twin data, it is thought that a high-quality smart city can be realized.

• Journal of the Korea Computer Graphics Society
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• v.7 no.2
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• pp.29-35
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• 2001

In general, image-based virtual environment is represented by panoramic images created by image mosaic algorithm. The cylindrical panoramic image supports the fixed-viewpoint navigation due to the constraints of construction. Shum proposed concentric mosaics to allow users to navigate freely within a circular area[10]. It is constructed by a sequence of images which is acquired from a regularly rotating camera. Concentric mosaics technique, proposed by Shum, is considered as 3D plenoptic function which is defined three parameters : distance, height and angle. In this paper, we suggest an effective method for creating concentric mosaics, in which we first align a set of strip images on the cylinder plane and stitch the aligned strips to build a panoramic image. The proposed method has no constraints such as regular panning motion of camera. Furthermore, our proposed method minimizes the use of interpolation image to create a novel view images from the concentric mosaics. It allows the result image on a novel view to have better quality with respect to the number of input images.