Patent ID: 7789562

Claim:
A method for calibrating a multi-plane X-ray unit, comprising: setting a reference projection geometry with respect to a first radiographic plane of the unit; defining an internal projection matrix of the first radiographic plane for mapping a spatial coordinate system internal to the unit onto an image coordinate system of the first radiographic plane in the reference projection geometry; capturing a first image data at a plurality of calibration points by the first radiographic plane in the reference projection geometry; determining an external projection matrix of the first radiographic plane for mapping a spatial coordinate system external to the unit onto the image coordinate system of the first radiographic plane based on the first image data and coordinates of the calibration points; capturing a second image data at the calibration points by a second radiographic plane of the unit; determining an external projection matrix of the second radiographic plane for mapping the spatial coordinate system external to the unit onto an image coordinate system of the second radiographic plane based on the second image data and the coordinates of the calibration points; and determining a measure of a position of the second radiographic plane based on the internal projection matrix and the external projection matrix of the first radiographic plane as well as the external projection matrix of the second radiographic plane.