房屋的三维几何特征在航空影像中的投影性质

Projection Properties of Building’s 3D Geometric Features in an Aerial Image

研究了三维现实场景中直角平顶房屋的屋顶、墙体、阴影在航空摄影时的投影性质,以及它们在航空影像中相应的二维几何特征。文中推导出了若干有关的计算公式,使用这些公式可以做到:①算出三维现实场景中的直角在航空影像中的角度;②从航空影像中有关墙体和阴影的二维特征信息算出平行投影中的视角参数以及三维现实场景中房屋高度、日照方向等。

This paper represents projection properties of roofs, walls and shadows of the buildings with right angle and flat roofs in 3D scene in the projection process of aerial images and educes some related computation formulae of two-dimensional geometric properties. These newly presented formulae are useful in the following aspects: ① to compute the projected angle for a right angle in 3D scene in an aerial image; ② to compute the view parameters of parallel projection in 3D scene such as tilt angle, height of building and direction of illumination, etc, from the two dimensional parameter information related to walls and shadows of buildings.