• Title/Summary/Keyword: Vegeation filters

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Vegetation filtering techniques for LiDAR data of levees using combined filters with morphology and color (형태와 색상의 복합형 필터를 이용한 제방 LiDAR 측량 데이터의 식생 영상 제거 기법 연구)

  • Park, Heeseong;Lee, Du Han
    • Journal of Korea Water Resources Association
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    • v.56 no.2
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    • pp.139-150
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    • 2023
  • Terretial LiDAR surveying is highly useful for maintenance of civil facilities as it can easily detect the temporal deformation of structures or topography. However, for river facilities such as levess, it is difficult to detect the deformation of the topography or structure under vegetations due to the influence of vegetation. Vegetation filters can be divided into color filters and morphological filters. In this study, combined filters with color and morphology are developed to improve the accuracy of vegetation filters. 8 color filters, 6 morphological filters, and 4 combined filters are applied to the vegetation removal on the embankment slope, and their accuracy and calculation time are compared. Color filters show a short calculation time, but the accuracy was low in the vegetation area. Morphological filters show high accuracy in the vegetation area, but low accuracy in places with severe local topographical changes such as heavy rocks. Combined filters also show a tendency similar to morphological filters, but in the case of ExGGM, the accuracy is excellent in both the vegetation and rock area. Considering the accuracy and calculation time, the combined filter ExGGM is suitable for general cases, and the shape filter GrMIn or the complex filter ExGISL is suitable for cases where the local topographical change is not severe.