近來三維數值城市及數碼城市(Cyber City)為各界極欲發展及研究的課題,為了要增加三維數值城市的擬真性及美觀程度,通常是將建物模型敷貼真實拍攝之牆面影像,增加三維模型的細緻化程度。而欲精確的敷貼牆面紋理影像,必須嚴密地將所拍攝之近景影像定位定向,一般採用光束法區域平差解算,此時需加上適當的控制點控制資訊才能完成,因此控制點控制資訊若來自地面測量將相當耗費成本。多年來,各地方政府製作大比例尺地形圖時已拍攝相當多的航照影像,可用來做為上述的控制資訊,亦即航空影像控制實體,若能使用這些航空影像控制實體作為控制資訊,不但可有效利用資源,亦能減少控制點取得所需花費的成本。因此,本研究將使用航空影像控制實體所提供的控制資訊做為控制來源。
本研究探討以航空影像控制實體作為控制資訊時,使用非量測型相機以類似傳統航測拍攝方式及旋轉多基線交向拍攝方式拍攝涵蓋建物牆面的目標區影像後,於最少控制且不同控制分布時,對光束法區域平差精度之影響。因使用非量測型相機,故本研究先以iWitnessPRO近景攝影測量軟體率定相機參數,接著以PHIDIAS近景攝影測量軟體解算光束法區域平差。過程中探討使用航空影像控制實體作為控制資訊時,於最少控制且不同控制分布時,加入附加參數解算的自率光束法區域平差與與一般光束法區域平差之精度。根據實驗結果,低樓層取像的光束法區域平差之檢核點RMSE精度,其結果大多可應用於LOD 3精度等級的牆面敷貼。另,因都市地區高樓林立,狹小巷弄多,有鑒於此,本研究使用旋轉多基線交向攝影,結果顯示其將有機會運用於近景攝影測量LOD 3精度等級的牆面紋理敷貼。 / Recently, the studies about the cyber city have become a popular topic. For improving the level of detail of cyber city, photo-realistic textures from images are mapped onto the surfaces of 3D building models. Before the accurate texture mapping, bundle block adjustment can be performed to recover the parameters of exterior orientation for each close-range images more accurate and more precise, where the control information is necessary. For the past years, many aerial photogrammetry projects were done by local governments for the mapping of 1/1000 topographic maps. Those historic aerial images can be used as control information to reduce the cost and increase the efficiency. Therefore, this study investigates the accuracy of bundle block adjustment about non-metric close-range images, taken from the ways similar to the traditional aerial photogrammetry and the rotating multi-baseline photogrammetry, by using control entities from historic aerial images as the minimal controls under various control distributions. Since the non-metric camera is used for collecting the close-range images, the iWitnessPRO software is utilized for camera calibration. After that, the PHIDIAS software, a close-range photogrammetry software, is employed to performed the bundle block adjustment. During performing the bundle block adjustment, the camera parameters are regarded as unknowns and determined, called as self-calibration bundle adjustment. The results of self-calibration bundle adjustment will be compared with conventional bundle adjustment.
The test results show that the accuracy of most self-calibration bundle adjustment about close-range images covered with low buildings can be used for the application of LOD 3 texture mapping. Moreover, the test results of using close-range images from rotating multi-baseline photogrammetry in urban areas show the potential possibility for LOD 3 texture mapping in urban areas with high buildings and narrow alleys.
Identifer | oai:union.ndltd.org:CHENGCHI/G0100257028 |
Creators | 林汝晏, Lin, Ju Yen |
Publisher | 國立政治大學 |
Source Sets | National Chengchi University Libraries |
Language | 中文 |
Detected Language | English |
Type | text |
Rights | Copyright © nccu library on behalf of the copyright holders |
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