'IFilinearity 01 'lhree Yerspect ive
It has been established that certain trilinear froms of three perspective views give rise to a tensor of 27 intrinsic coefficients [ll]. We show in this paper that a permutation of the the trilinear coefficients produces three homograph y matrices (projective t ransfonn at ions of planes) of three distinct intrinsic planes, respectively. This, in turn, yields the result that 30 invariants are recovered directly - simply by appropriate arrangement of the tensor’s coefficients. On a secondary level, we show new relations between fundamental matrix, epipoles, Euclidean structure and the trilinear tensor. On the practical side, the new results extend the existing envelope of methods of 30 recovery from 20 views -for example, new linear methods that cut through the epipolar geometry, and new methods for computing epipolar geometry using redundancy available across many views.