Abstract: Vanishing point has many geometry attributes and exists abundantly in building
scenes, based on this, a camera calibration method is proposed using vanishing points, which is
especially used for building reconstruction. Lots of geometry constraints are discovered, such as
the constraint relationship between vanishing points and camera matrix, the origin of world
coordinate system and camera matrix. Then through matrix reconstruction and Euclid
reconstruction, the camera matrix is calculated. Through decomposition of this matrix, the inner
and outer parameters of the camera are achieved. In this method, no calibration object is needed;
besides, it also has the advantage of simple calculation process, high calibration speed.
Experiments show that it can meet the needs of building reconstruction in virtual reality system.

Key words: image based modeling, computer vision, vanishing point, camera matrix;
pinhole camera model