Előadás címe: On the reconstruction of the center of the projection by distances and incidence relations – theory and practice
Helyszín: Online
Időpont: 2020.06.30., 14:40 – 15:00
Kivonat: Photographic images are produced by a central projection of a restricted area in the space onto the image plane. To obtain reliable information about physical objects and the environment through the process of recording is the basic problem of photogrammetry. Our aim is to reconstruct the center of the projection by distances and incidence relations. The distance part means that we know the distance between the point to be projected and the center of the projection. The incidence part means that we know (at least) three collinear points to be projected. They can be detected by the help of images of special objects (facade, roadway, curb-stone, lamp-post etc.). Combining these information we can construct a surface of revolution containing the center of the projection. It is a generalized conic all of whose points have a zero weighted distance sum from the elements of the (collinear) triplet of the projected images. Six collinear points in the space allow us to construct a spherical surface containing the center of the projection. Such a sphere is centered at the image plane and the process ends when you find three spherical surfaces with non-collinear centers. Up to the symmetry about the image plane their intersection determines the center of the projection.