Single-shot camera position estimation by crossed grating imaging

A simple method to estimate the position of a camera device with respect to a reference plane is proposed. The method utilizes a crossed grating in the reference plane and exploits the coordinate transformation induced by the perspective projection. If the focal length is available, the position of the camera can be estimated with a single-shot. Otherwise, the focal length can be firstly estimated from few frames captured at different known displacements. The theoretical principles of the proposed method are given and the functionality of the approach is exhibited by correcting perspective-distorted images. The proposed method is computationally efficient and highly appropriate to be used in dynamic measurement systems.