Camera calibration using two or three vanishing points

The perspective projection models the way a 3D scene is transformed into a 2D image, usually through a camera or an eye. In a projective transformation, parallel lines intersect in a point called vanishing point. This paper presents in detail two calibration methods that exploit the properties of vanishing points. The aim of the paper is to offer a practical tool for the choice of the appropriate calibration method depending on the application and on the initial conditions. The methods, using two respectively three vanishing points, are presented in detail and are compared. First, the two models are analyzed using synthetic data. Finally, each method is tested in a real configuration and the results show the quality of the calibration.