• Title/Summary/Keyword: Digital photographs

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Utilization Methods and Generation DEMs by Using Aerial Photographs (항공사진을 이용한 수치표고모형 생성과 활용방안)

  • Choi, Hyun;Hong, Soon-Heon
    • The Journal of the Korea Contents Association
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    • v.7 no.3
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    • pp.168-175
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    • 2007
  • The flood caused landslide disaster each year because of climate change. And the change of topography from an earthquake makes topographical analysis impossible. This paper performed an investigation about a utilization methods and generation DEM(Digital Elevation Model) after digital aerial photographs quickly when the topographical change happens. Stereo imagery that was collected through digital aerial photographs made a generation of DEM possible. A standard deviation of generated DEM is 0.864m which is somewhat high but shows the real topography. As a result, it should be possible to generate DEM by using aerial photographs in case of the change of topography.

A Study on 3-D Landscape Modeling by Digital Photographic Images (항공사진영상에 의한 3차원경관모델링 실험)

  • Seok Jin-Chang;Lee Jun-Hyuk;Kim Yi-Ho;Lee Young-Jin
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.217-222
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    • 2006
  • In this study, we performed three dimensional(3-D) modeling and simulation of terrain surfaces by using large scale aerial photographs. The objectives of this study are to use landscape analysis including 3-D database of built environments. The test area is selected around Olympic stadium located in Susung-gu, Daegu. A 1:5,000 scale of ortho-photo map is generated by photogrammetric procedures from 1:20,000 scale of aerial photographs, Digital Elevation Model (DEM) is also extracted from stereo aerial photographs or digital maps. The heights of buildings are determined using GPS control survey and aerial photographs in the test area, DEMs are extracted from the digital map. And then the two are combined three-dimensional changes of landscape views of buildings with terrain are simulated.

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Advanced National Base Map by Using High-Resolution Digital Aerial Photograph (고해상도 디지털 항공사진을 이용한 국가기본도 고도화 방안)

  • Lee, Hyun-Jik;Koo, Dae-Sung;Park, Chan-Ho
    • Journal of Korean Society for Geospatial Information Science
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    • v.18 no.1
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    • pp.135-143
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    • 2010
  • The national base map has its value sand roles as the basic spatial information of the nation. The current national base map that is a 1/5,000 digital map, however, has failed to perform its roles as basic spatial information due to the limitations with its quality and accuracy and requires measures to complement them. Thus this study set out to suggest ways to advance the current 1/5,000 national base map, selected topography and natural features of a digital map that could be made with GSD 0.25m digital aerial photographs, and set up the optimal ways to make a digital map by conducting an experiment of making an optimal digital map with such photographs. It also analyzed the map made with GSD 0.25m digital aerial photographs for accuracy and usability. In order to establish a set of criteria of making a digital map with GSD 0.25m digital aerial photographs, the investigator carried out analyses and picked topography and natural features items, which include 9 large categories, 31 medium categories, and 509 small categories. Then an experiment of making a digital map was conducted according to the digital map making method. As a result, solid drawing was selected as the optimal way to making a digital map, and the optimal process was established. Using the research achievements, a model digital map was made with GSD 0.25mm digital aerial photographs. The map recorded about two times horizontal and vertical location accuracy than the old 1/5,000 digital map and was capable of detailed descriptions of topography and natural features. A new national base map made with GSD 0.25m digital aerial photographs will provide reliable spatial data, thus increasing the level of satisfaction among people and the level of advancement of national base maps.

Development of Mosaic Aerial Photographs for Shoreline Change Study in Nakdong Estuary (낙동강 하구 해안선변화 연구를 위한 모자이크 항공사진의 구축)

  • Kim, Baeck-Oon;Khim, Boo-Keun;Lee, Sang-Ryong
    • Ocean and Polar Research
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    • v.27 no.4
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    • pp.497-507
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    • 2005
  • This paper presents a method for obtaining mosaic aerial photographs that are useful for a long-term shoreline change study in the Nakdong estuary. Although this method involves digital photogrammetry software of the shelf its usage can be simplified to accomodate the shoreline change study. Ground control points, which are common in aerial photographs, were measured from digital maps. Block triangulation was highly affected by land-based GCPs. Extension of tie points near the shoreline to vertical control points gave more reliable results for the block triangulation. A constant Digital Elevation Model (DEM), close to mean sea level, was employed to produce ortho-rectified photographs, from which mosaic photographs were made. Accuracy of photographs were found to be acceptable for the analysis of long-term shoreline change, and the promising construction of a shoreline change database in the Nakdong estuary.

Appropriate Digital Camera System for Digital Ultraviolet Photography (디지털 자외선 사진을 위한 적정 디지털 카메라 시스템)

  • Lee, Young-Kyu;Har, Dong-Hwan
    • The Journal of the Korea Contents Association
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    • v.10 no.7
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    • pp.40-48
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    • 2010
  • Reflected-Ultraviolet photography is applied to the evidence of crime, Archaeology, and Dermatology. In the past, Ultraviolet photography was done with standard black-and-white film. Because emulsion of film is more sensitive to near UV light than CCD(Charge Coupled Device) or CMOS(Complementary Metal-Oxide-Semiconductor)of digital camera. In this research, we purpose to improve qulity of ultraviolet photographs and to find out the best alternative digital camera by utilizing a cunsumer digital camera. To achieve theses, we removed IR cutoff filter from digital camera. And by using modified UV pass filter, we verified the increase of image resolution of digital ultraviolet photographs. Also, we analyze reproducibility of digital ultraviolet photographs according to type, size, pixel of image sensor. Furthermore, this research resulted in the development of an practical digital camera system by utilizing a cunsumer digital camera. Eventually, it will contribute to practical use in the various field of digital ultraviolet photographs

Digital Image Processing Technique for Measurements from Non-metric Photographs (비측정용 사진의 측정을 위한 수치화상처리기법의 적용)

  • 안기원;박병욱
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.13 no.2
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    • pp.199-208
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    • 1995
  • Significant developments in the use of digital imagery for close-range photogrammetric metrology have occured in the last few years because of technological advances in digital image processing. Present day needs for applications of digital image processing technique to measurements of photographs obtained with non-metric camera at reduced cost, automation and convenience. In order for this application to be useful, a detailed procedure must be developed. Investigation of this study is given to the detailed procedure for the digital measurements of the object space data from the scanned non-metric photographs.

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A Study on Constructing of Photographic Digital Archive : Focusing on the Photographs of Korean Democratization Movements (사진 디지털아카이브 구축에 관한 연구 : 민주화운동 사진기록을 중심으로)

  • Kim, Myoung-Hun;Hyun, Jong-Chul
    • Journal of Information Management
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    • v.37 no.3
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    • pp.139-163
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    • 2006
  • This article analyze a constructing process of photographic digital archive based on photographs of korean democratization movements. After photographic digital archive defines as integrated systems in which photographic digital objects collect, classify, describe, preserve and access, this article explains metadata elements and classification schema reflecting a special quality of photograph. Especially, this article presents dynamic classification structure using subject keywords. After all, this method provides integrity and interrelationship with photographes which promote usability of photographic digital objects.

A Study on the Digital Photographic Evidence in Police's Criminal Investigation Activity (경찰의 범죄수사활동에 있어 디지털 영상매체의 활용에 관한 연구)

  • Han Sang-Am
    • The Journal of the Korea Contents Association
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    • v.6 no.5
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    • pp.153-160
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    • 2006
  • Recently, digital imaging is frequently used by crime scene investigators. However, the admissibility of digital photographic evidence in court is often raised because of the fact that digital photographs are more easily modified than film-based photographs. Therefore, in this article, the researcher reviewed some basic theories and legal considerations related with police crime scene investigations in Korea and The United States. This article is presented in the hope of clearing up some of the possibilities of falsifying photographic evidences and in the hope of setting the strict the rules of evidence regarding digital evidence in this county.

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Generation of 3 Dimensional Image Model from Multiple Digital Photographs (다중 디지털 사진을 이용한 3차원 이미지 모델 생성)

  • 정태은;석정민;신효철;류재평
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1634-1637
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    • 2003
  • Any given object on the motor-driven turntable is pictured from 8 to 72 different views with a digital camera. 3D shape reconstruction is performed with the integrated software called by Scanware from these multiple digital photographs. There are several steps such as configuration, calibration, capturing, segmentation, shape creation, texturing and merging process during the shape reconstruction process. 3D geometry data can be exported to cad data such as Autocad input file. Also 3D image model is generated from 3D geometry and texture data, and is used to advertise the model in the internet environment. Consumers can see the object realistically from wanted views by rotating or zooming in the internet browsers with Scanbull spx plug-in. The spx format allows a compact saving of 3D objects to handle or download. There are many types of scan equipments such as laser scanners and photogrammetric scanners. Line or point scan methods by laser can generate precise 3D geometry but cannot obtain color textures in general. Reversely, 3D image modeling with photogrammetry can generate not only geometries but also textures from associated polygons. We got various 3D image models and introduced the process of getting 3D image model of an internet-connected watchdog robot.

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A Study on Restoration and Utilization of Recorded Archaeological Data (기록화된 고고자료의 복원과 활용방안에 대한 연구)

  • Heo, Ui-Haeng
    • Journal of Digital Contents Society
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    • v.18 no.4
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    • pp.723-731
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    • 2017
  • The restoration of archaeological data was carried out using photographs and drawings left as past records. It can be divided into ruins and artifacts. The restoration of the ruins was performed by modeling the individual parts and parts left by the photographs, aligning them and synthesizing them, and reconstructing them three-dimensionally as one object. Restoration of artifacts was performed on both photographs and drawings. After the modeling work is prioritized through the photographs, there is a method of restoring the original image by modifying the texture image of the damaged part of the modeled artifact, or restoring the original image by modeling and synthesizing the deleted part in the artifact. The restoration of the artifacts through the drawings was carried out by three - dimensional modeling and reconstruction through real mapping of images. The reconstructed archaeological data can be used in various directions. In particular, it is possible to verify and compare the results of the numerical analysis and interpretation of the past 2D data, and to provide a more accurate analysis plan in the future.