An apparatus for determining rectifying homographies for a linear camera array with a common baseline and co-oriented is configured to provide feature point triplets in three images of a scene captured by three cameras of the linear camera array; using positions (u,v), (υ',&ngr;'), (u",v") of the feature point triplets, form, per feature point triplet, a linear equation of type Ax = b, where x is a vector the components x j. of which comprise geometric parameters, and A is a matrix and b is a vector, both dependent on the positions (u, v), (υ',&ngr;'), (u",v") of the respective feature point triplet such that Ax = b is rewriteable into (formula 1), where T 1, T 2, T3 are correlation slices of a trifocal tensor the elements (formula 2) of which relate to projection matrices P, (formula 3) describing the projections of a first, second and third of the three cameras, respectively.