Figure 9.
The local coordinate system of the stereovision camera. F is the focus of the camera, and f is the focal length, (x,y,z) are the coordinates of a point in the camera coordinate system. This point has the coordinates (xP, yP, 0) on the projection plane PP of the camera and α denotes the angle from the Z axis at which point (x, y, z) is visible by the camera.