We present a method for estimating unknown geometric entities based on
identical, incident, parallel or orthogonal observed entities. These
entities can be points and lines in 2D and points, lines and planes in
3D. We don't need any approximate values for the unknowns. The
entities are represented as homogeneous vectors or matrices, which
leads to an easy formulation for a linear estimation
model. Applications of the estimation method are manifold, ranging
from 2D corner detection to 3D grouping.