A fundamental domain D for T2 is a connected closed subset D c H behaving like the quotient space T2 \ H, at least up to boundary identifications. Thus, for every z g H, there is a y G T2 such that yz g D. Moreover, if z and w lie in the interior of D and z = yw for y G T2, then y = ±1, where / is the identity matrix. It is easily seen (cf. Terras [17]) that the region (1.1) F2= (zg//| -i< Rez<...

The image points in two images satisfy epipolar constraint. However, not all sets of points satisfying epipolar constraint correspond to any real geometry because there can exist no cameras and scene points projecting to given image points such that all image points have positive depth. Using the cheirality theory due to Hartley and previous work on oriented projective geometry, we give necessa...