• Journal of the Korean Geophysical Society
• /
• v.7 no.4
• /
• pp.247-253
• /
• 2004

In this paper, 3D recognizing algorithm which is based on the external shape feature is presented. Since many objects have the regular shape, if we posses the database of pattern and we recognize the object using the database of the object's pattern, it is possible to inspect and/or recognize the objects of many fields. This paper handles on the 3D object recognition algorithm using the geometrical pattern matching by 3D database.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.6
• /
• pp.874-880
• /
• 2018

3D modeling is extensively used in the field of architecture, machinery and contents production such as movies. Modeling is a time-consuming task. In order to compensate for these drawbacks, attempts have recently been made to reduce the production period by applying 3D scanning technology. 3D scanning for small objects can be done directly with laser or optics, but large buildings and sculptures require expensive equipment, which makes it difficult to acquire data directly. In this study, 3D modeling data for a large object is acquired using photometry with using drones to acquire the image data. The maintenance method for uniform spacing between the sculpture and the drone, the measurement method for the flight line were presented. In addition, we presented a production environment that can utilize the obtained 3D point cloud data for animation and a rendered animation result to find ways to make it in various environments.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.5D
• /
• pp.869-876
• /
• 2006

In the case of earthenware cultural heritages that are found in the form of fragments, the major task is quick and precise restoration. The existing method, which follows the rule of trial and error, is not only greatly time consuming but also lacked precision. If this job could be done by three dimensional scanning, matching up pieces could be done with remarkable efficiency. In this study, the original earthenware was modeled through three-dimensional pattern scanning and photogrammetry, and each of the fragments were scanned and modeled. In order to obtain images from the photogrammetry, we calibrated and used a Canon EOS 1DS real size camera. We analyzed the relationship among the sections of the formed model, efficiently compounded them, and analyzed the errors through residual and color error map. Also, we built a web-based three-dimensional simulation environment centering around the users, for the virtual museum.

• Conservation Science in Museum
• /
• v.22
• /
• pp.15-26
• /
• 2019

This study was focused on the three-dimensional convergence modeling that can multilaterally analyze internal and external shapes of the Sam-Chongtong Hand Canon by optical precision scanning optimized for acquiring the surface shape and X-ray CT scanning used for obtaining the internal shape. First, the scanning results were converted by compatible extension, after which three-dimensional deviation analysis was conducted to verify mutual conformities. Accordingly, most (56.98%) deviations between the two scanning models was found be ±0.1mm. This result did not influence registration and merging based on the ICP algorithm. The merged data exhibited the external surface color, detailed shapes, internal width, and structure of the hand canon. The three-dimensional model based on optical surface scanning and X-ray CT scanning can be used for traditional technique interpretation as well as digital documentation of cultural heritage. In the future, it will contribute to deliver accessible scientific information of exhibits for visitors.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.4
• /
• pp.242-247
• /
• 2017

Over- and under-excavation are factors that increase construction cost of tunnels, which makes management essential. Total stations have been used for tunnel surveying because GNSS is difficult to use in tunnels. However, it takes much time to acquire data using total stations. In this study, a total station was integrated with a 3D laser scanner and used for tunnel surveying in Namyangju-si, Gyeonggi-do. The scanning total station reduced the work time compared to the conventional method. Furthermore, reports were effectively generated for overbreak and underbreak for each section and compared with the design. In addition, we could analyze both the cross section and scanned area effectively by using the scanning data. This method can improve the efficiency of tunnel surveying work by combining the advantages of a conventional total station and a 3D laser scanner.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.11
• /
• pp.1660-1665
• /
• 2022

Recently, many industries are using three dimensional scanning technology. As the performance of the 3D scanner gradually improves, a sampling step to reduce a point data or a remove step to remove a part determined to be noise are generally performed in post processing. However, total point data by long time scanning cannot be processed at once in spite of performing such those additional processes. In general, a method using a multi threaded environment is widely used, but as the scanning process work time increases, the processing performance gradually decreases due to various environmental conditions and accumulated operations. This paper proposes a method to initially remove point data judged to be unnecessary by calculating accumulated fast point feature histogram values from coming point data of the 3D scanner in real time. The entire 3D scanning process can be reduced using this approach.

• 한국지형공간정보학회:학술대회논문집
• /
• 2002.03a
• /
• pp.23-26
• /
• 2002

시설물 관리 시스템 또는 GIS의 구축에 있어서 도형 정보는 주로 대상물의 2차원 평면 형상과 위치 정보로 구성되어 있다. 따라서 대상물의 실제 형상적 특성과 주변 환경과의 관계를 입체적으로 규명하기 위해서는 3차원 정보가 필요하다. 3차원 정보는 점, 선, 면으로 구성되는 기존 공간 데이터의 경직성을 탈피하고 현실적 세계를 표현할 수 있는 장점이 있다. 특히 기존의 측정 개념으로 접근 할 수 없는 영역에 대한 정보를 획득할 수 있으며, 복잡하고 다양한 형태의 대상물에 대한 정보의 획득이 용이하다. 본 연구에서는 실험적으로 3D 레이저 스캐닝 시스템을 적용하여 공간 데이터를 획득하고 데이터의 특성을 분석하였으며, point cloud 데이터의 처리 및 관리 시스템과의 연계 방안을 제시하고자 하였다.

• Journal of Conservation Science
• /
• v.25 no.2
• /
• pp.115-130
• /
• 2009

This study was focused on digital restoration and structural stability evaluation applying 3D scanning system of five-storied Magoksa temple stone pagoda in Gongju. For these, the digital restoration of the pagoda was completed using laser scan data which is measured 16 directions and data processing program of 7 stages. As a result of digital restoration, the overall height and width of stone properties showed a little difference in directions and the width of roof stones appeared very high difference of each floor. The width of pagoda body become smaller to the fifth floor, but gradual decrease rate showed irregular characteristics. Also, as result of 3D image analysis for structural stability evaluation, the displacement occurred toward northwest in second body stone to upper final stone except for central axis of the first body stone which inclines toward southwest. Such 3D image analysis is required quantification of survey method and should be applied to various field such as quantitative damage maps in order to utilize a conservation of stone cultural heritages, continuously.

• Journal of Cadastre & Land InformatiX
• /
• v.49 no.2
• /
• pp.57-66
• /
• 2019

Recently, as a part of the production of spatial information by smart cities, three-dimensional reproduction of structures for reverse engineering has been attracting attention. In particular, terrestrial LiDAR is mainly used for 3D reproduction of structures, and 3D reproduction research by UAS has been actively conducted. However, both technologies produce blind spots due to the shooting angle. This study deals with vertical structures. 3D model implemented through SfM-based image analysis technology using UAS and reproducibility and effectiveness of 3D models by terrestrial LiDAR-based laser scanning are examined. In addition, two 3D models are merged and reviewed to complement the blind spot. For this purpose, UAS based image is acquired for artificial rock wall, VCP and check point are set through GNSS equipment and total station, and 3D model of structure is reproduced by using SfM based image analysis technology. In addition, Through 3D LiDAR scanning, the 3D point cloud of the structure was acquired, and the accuracy of reproduction and completeness of the 3D model based on the checkpoint were compared and reviewed with the UAS-based image analysis results. In particular, accuracy and realistic reproducibility were verified through a combination of point cloud constructed from UAS and terrestrial LiDAR. The results show that UAS - based image analysis is superior in accuracy and 3D model completeness and It is confirmed that accuracy improves with the combination of two methods. As a result of this study, it is expected that UAS and terrestrial LiDAR laser scanning combination can complement and reproduce precise three-dimensional model of vertical structure, so it can be effectively used for spatial information construction, safety diagnosis and maintenance management.

• Journal of Conservation Science
• /
• v.27 no.2
• /
• pp.181-190
• /
• 2011

A precision measurement and digital image restoration of the 5th century's gilt bronze cap of Baekje dynasty, excavated from the ancient tomb of Andong, Goheung in 2006, was undertaken. The objective of the scanning is to preserve precise feature of the artefact in the form of digital data by embodying it in 3 dimensional space. Acquirement of the data has been undertaken in the following process : 3D scanning to obtain 3D shape and color information(original data photographing)-3D modelling(joining original data and restoring non-photographed or damaged area)-CG image production. Production of restoration CG image was based on joined shape of original data and each part's measurement on CAD. Non-photographed part and area of loss was restored referring actual measurement and research result of excavated cap from the 5th to 8th century. 3D image restoration is one of artefact restoration methods which restores artefact without risk. It is also undertaken with historical research. As result, this method can enhance aesthetic and academic value of the artefact by successful restoration.