本研究從資訊融合角度出發，結合光達資料及數位化彩色空照影像進行三維建物模型之重建。本研究分成兩個部分，第一部份是房屋區塊偵測，第二部份是房屋模型重建。 房屋區塊偵測部分，依原始光達資料之高度資訊，判別出地上物區域。利用空照影像之色彩分析，將地上物區域之樹木部分去除。殘餘之區塊設定一面積門檻，將面積過小之區塊濾除。之後進行區塊形狀以及表面分析，去除不合理之區塊，房屋區塊即建立完成。 房屋模型重建部分，首先進行光達資料前處理，預估出概略屋緣位置，同時萃取出位於屋頂平面之光達點。將預估之概略屋緣位置投影至空照影像上，設定工作區域，在此區域內進行精確之直線偵測。所得之直線線段組合成房屋之候選屋頂面，搭配前處理中萃取出之光達點進行屋頂面之判別與高度計算後，投影回物空間獲得三維之屋頂面，最終結合SMS方法建立房屋模型。研究中使用新竹科學園區之光達資料及大比例尺數位空照影像進行測試。 From the viewpoint of data fusion, we integrate LIDAR data and digital aerial image to perform 3D building modeling in this study. The proposed scheme comprises two major parts: (1) building block detection and (2) building model reconstruction. In the first step, height differences from LIDAR data are analyzed to detect the above ground areas. Color analysis is then performed for the exclusion of tree areas. Remaining regions are restricted by area threshold. After the refinement by shape and texture analysis, building blocks are established. In the second step, we analyze the height information of LIDAR raw data to estimate the approximate roof-edges and extract the LIDAR points located on the rooftop. Based on the approximate roof-edges, accurate 2D edges are calculated in aerial image and then transformed into candidate roof-planes. Combined with the extracted LIDAR points, the correct roof-planes are selected and projected back to object space as 3D roof-planes. At last, a patented method SMS (Split-Merge-Shape) is employed to generate building models using the 3D roof-planes. LIDAR data and large scale aerial image in Hsin-Chu Science-based Industrial Park of north Taiwan were used in the test.
