Automated subpixel image registration of remotely sensed imagery

An algorithm is described for the automated registration of remotely sensed imagery that registers 6000 × 6000-pixel images in 8–18 minutes on an IBM RISC System/6000® workstation. The resulting registration is accurate to the subpixel level even in the presence of noise and large areas of change in the images. It is shown that the registration- mapping function for parallel projections has the form F(x,y) = A(x,y) + h(x,y)e, where A(x,y) is an affine transformation, h(x,y) is a function that depends on the topographic heights, and e is a vector that defines the epipolar lines. The algorithm determines the parameters of this equation using only the image data, without knowledge of the viewing orientations or scene point coordinates. The search for match points is then a one-dimensional search along the epipolar lines, which greatly increases the speed and accuracy of the registration.