| 摘要 |
PURPOSE: A building extracting method is provided to extract an improved building boundary line by local filtering raw lidar point data measured by an aerial layer. CONSTITUTION: A building extracting method comprises setting initial assumption values to a building maximum size, a building minimum area, a building height, and an interval between buildings(a10). Points of outliers owing to an error and an underpass are removed from lidar data(a20). After applying a window to raw lidar point data, in which the outliers are removed, points having a height over a predetermined value are selected from points in the window so as to extract an initial building point(a30). After forming a triangulated irregular network from the initial building point, an initial building boundary line corresponding to a boundary of each building is extracted by removing a line and a polygon not corresponding to a building from the triangulated irregular network(a40). After endowing a building polygon identification to the initial building boundary line, a final building point and a boundary line are extracted by removing points, in which a height difference over a predetermined value exists, from points of the same polygon identification(a50). After applying Hough transform and an area condition to the final building boundary line, a final building polygon and particular point data are extracted by extracting characterized points of a linear building boundary(a60).
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