 Given the two cameras 1 and 2, we have the camera equations:
and
 The optical center projects as
 Writing
where
is
nonsingular we have that
is the optical center.
 The epipole
in the second image is the projection of the
optical center of the first image:
 The projection of point on infinity along the optical ray
on to the second image is given by:
 The epipolar line
is given by the
cross product
.
 If
is the
antisymmetric matrix representing cross product with
,
then we have that the epipolar line is given by
 Any point
on this epipolar line satisfies

is called the fundamental matrix. It is of rank 2 and
can be computed from 8 point correspondences.
 Clearly
(degenerate epipolar line) and
. The epipoles are
obtained as the null spaces of
.
Subhashis Banerjee
20080121