• Title/Summary/Keyword: Building edge buffer

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Shadow Extraction of Urban Area using Building Edge Buffer in Quickbird Image (건물 에지 버퍼를 이용한 Quickbird 영상의 도심지 그림자 추출)

  • Yeom, Jun-Ho;Chang, An-Jin;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.2
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    • pp.163-171
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    • 2012
  • High resolution satellite images have been used for building and road system analysis, landscape analysis, and ecological assessment for several years. However, in high resolution satellite images, shadows are necessarily cast by manmade objects such as buildings and over-pass bridges. This paper develops the shadow extraction procedures in urban area including various land-use classes, and the extracted shadow areas are evaluated by a manually digitized shadow map. For the shadow extraction, the Canny edge operator and the dilation filter are applied to make building edge buffer area. Also, the object-based segmentation was performed using Gram-Schmitt fusion image, and spectral and spatial parameters are calculated from the segmentation results. Finally, we proposed appropriate parameters and extraction rules for the shadow extraction. The accuracy of the shadow extraction results from the various assessment indices is 80% to 90%.

Rearrangement of the Designated Area and Modification of Features of Buryeongsa Valley as a Scenic Site (불영사계곡의 명승 지정구역 조정 및 현상변경 방안 연구)

  • Ahn, Seung-Hong;Hong, Youn-Soon;Kim, Hak-Beom
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.6
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    • pp.48-56
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    • 2010
  • Since ancient times, Korea has been called a land of beauty. Scenic sites under the Cultural Properties Protection Act include picturesque places that are famous for their natural scenic beauty as well as their historical and cultural value. Scenic sites are managed as natural assets to promote their preservation and use. However, the management of scenic sites can produce adverse effects on regional development and ownership rights. Moreover, the purpose of their designation as cultural assets is not fully understood because scenic sites are managed by focusing on restraint on users' act the same as was applied to historic sites. Therefore, the purpose of this study is to protect inhabitants' rights of ownership by arranging the boundaries of designated areas and by providing standard permission for condition changes in the Buryeongsa Valley, which was designated as a Scenic Site in 1979. The results of this study can be summarized as follows: First, arranging the boundaries of the designated area includes the arrangement of the edge lines standardized on the visual range of the mountain ridge, preventing the loss of landscape beauty in the designated district; the internal clearing district focuses on the existing settlement. Gearing the designated areas after the arrangement of the boundaries results in $11,928,932m^2$, 38.6% compared to the existing designated areas. Second, it establishes a 500m buffer zone inside the radius of the boundary of the cultural asset as a standard for condition changes that seriously affect landscape preservation. Third, the standards for permission on building 'height regulations' are divided into flat and gable, according to the roof shape. The adopted standard is 8m high for 2 story flat roofs, and 12m high for 2 story gable roofs.

Consideration on how to build on AndongJotap-ri five-story brick pagoda using the building methodology of a stone pagoda between the 7th~9th century (7~9세기 석탑조영방법을 통해 본 안동 조탑리 오층전탑의 조영방법 고찰)

  • Kim, Sang-Gu;Lee, Jeong-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.744-754
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    • 2015
  • Buddhist temple construction at East Asia is considered one of the most important architecture activities together with the capital city and palace, where the pagoda is positioned at the center of a Buddhist temple as the most important element of Buddhist architecture enshrining Buddha's Sary. Accordingly, this study was performed to examine the procedure of how to build brick pagodas through the stone pagoda's internal structure between $7^{th}{\sim}9^{th}$ century while disassembling and repairing Andong Jotap-ri five-story brick pagoda. As a result, as the brick pagoda destruction phenomenon, there was a slip phenomenon by side forces, member's plastic temperature, and mixed material differences. Second, like a stone pagoda, brick pagoda is classified and constructed by the design and structural parts. According to the analysis, the design part is formed by the most edge brick, and the structure part places stone material at the buffer zone in the design brick from most edge brick and intra-center, i.e., at the space to support a side force while the top weight is vertically led. When building a brick pagoda, putting a wood pole at inside center plays the role as holding parts. In addition, the center axis is connected to the bottom of the steel pole hole, A steel pole hole has holes to safely settle down and decide the position. Because of them, the steel pole is self-loaded, which may be installed by wood rather than immovable steel.

Selective Histogram Matching of Multi-temporal High Resolution Satellite Images Considering Shadow Effects in Urban Area (도심지역의 그림자 영향을 고려한 다시기 고해상도 위성영상의 선택적 히스토그램 매칭)

  • Yeom, Jun-Ho;Kim, Yong-Il
    • Journal of Korean Society for Geospatial Information Science
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    • v.20 no.2
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    • pp.47-54
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    • 2012
  • Additional high resolution satellite images, other period or site, are essential for efficient city modeling and analysis. However, the same ground objects have a radiometric inconsistency in different satellite images and it debase the quality of image processing and analysis. Moreover, in an urban area, buildings, trees, bridges, and other artificial objects cause shadow effects, which lower the performance of relative radiometric normalization. Therefore, in this study, we exclude shadow areas and suggest the selective histogram matching methods for image based application without supplementary digital elevation model or geometric informations of sun and sensor. We extract the shadow objects first using adjacency informations with the building edge buffer and spatial and spectral attributes derived from the image segmentation. And, Outlier objects like a asphalt roads are removed. Finally, selective histogram matching is performed from the shadow masked multi-temporal Quickbird-2 images.

Analysis of Shadow Effect on High Resolution Satellite Image Matching in Urban Area (도심지역의 고해상도 위성영상 정합에 대한 그림자 영향 분석)

  • Yeom, Jun Ho;Han, You Kyung;Kim, Yong Il
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.2
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    • pp.93-98
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    • 2013
  • Multi-temporal high resolution satellite images are essential data for efficient city analysis and monitoring. Yet even when acquired from the same location, identical sensors as well as different sensors, these multi-temporal images have a geometric inconsistency. Matching points between images, therefore, must be extracted to match the images. With images of an urban area, however, it is difficult to extract matching points accurately because buildings, trees, bridges, and other artificial objects cause shadows over a wide area, which have different intensities and directions in multi-temporal images. In this study, we analyze a shadow effect on image matching of high resolution satellite images in urban area using Scale-Invariant Feature Transform(SIFT), the representative matching points extraction method, and automatic shadow extraction method. The shadow segments are extracted using spatial and spectral attributes derived from the image segmentation. Also, we consider information of shadow adjacency with the building edge buffer. SIFT matching points extracted from shadow segments are eliminated from matching point pairs and then image matching is performed. Finally, we evaluate the quality of matching points and image matching results, visually and quantitatively, for the analysis of shadow effect on image matching of high resolution satellite image.