數碼城市可以虛擬實境，於電腦環境中展現三維空間。所需的空間資訊，就幾何觀點而言，主要在於建置立體模型，因此這些物件在進行視覺化模擬時，需具備細緻的紋理特性，以達到仿真的效果。本研究利用空照影像，於現有之房屋模型，對牆面及屋頂面進行套合。一般而言，屋頂面遮蔽問題較為單純，牆面則較為嚴重，故須先處理遮蔽情況，再進行紋理影像敷貼。 本研究所使用資料，包括傳統空照影像與傾斜攝影直升機影像。處理概念主要為偵測牆面及屋頂面之遮蔽區，並對遮蔽區域以多視角影像進行補償。牆面部分所使用之影像，是基於影像傾斜攝影概念。對欲處理之目標牆面，應以影像傾斜攝影角度最大為優先，如此可得到影像解析度較佳之牆面影像，但相對的，牆面被其他建築物遮蔽的情況也較嚴重；本研究的重點，即為於這些影像中，找到最佳化的組合。屋頂面部分，則以垂直攝影影像，可得解析度較佳之屋頂面，在此以真實正射之概念進行影像套合。 研究主要包含幾個步驟：(1)資料前處理，(2)影像選擇，(3)遮蔽區判斷，(4)遮蔽區補償，(5)影像修補。研究中使用資料包括傳統航照影像、傾斜攝影直升機影像、數值高程模型、數值房屋模型，測試區域為台北市。 Cyber city displays 3D geoinformation for virtual reality in computer environments. On the geometric aspect, it is needed to establish 3D models. In the visualization, the objects need more details for texture to reach reality. This research registers aerial photos onto building facades. In which, building roofs and walls are to be treated. Generally, the occlusion of wall is more complicated than roof. Therefore, before texture mapping, we need to detect occlusions. This research uses traditional aerial photos and oblique helicopter images. The main task is to detect hidden areas for roofs and walls, then compensate them with multi-view images. The wall images that we choose are based on oblique photography. For the target wall, we should select the largest oblique angle for the prior image in order to get better resolution. However, the occlusion problem by neighboring buildings is more serious. It is the major task of this study to select the optimal combination of images. For the roof, we use the vertical photos to obtain better resolution. The essence of the step is to register the roof surface with images. The proposed scheme includes: (1) image selection, (2) hidden detection, (3) compensation for occlusions, (4) image registration, and (5) inpainting. The test data comprise traditional aerial photos, oblique helicopter images, digital elevation model, and three dimensional building models. The test site is in Taipei.
