“…The projections of the images, d1, i = 1,2, in the horizontal and vertical directions, respectively, are defined by d7(y) = >dj(X,y) (5) and d(x) = d(x,y) (6) The shifts are estimated from these projections by locating the peaks of the estimated one-dimensional crosscorrelation functions of the vector projections. In particular, we define the vertical and horizontal vector crosscorrelation functions respectively as, P(z) = >d(x)4(z+x) (7) and P(w) = d (y)d(w + y). (8) Using these statistics, the shifts are estimated independently as, Y2 maxP(z), (9) and in the other dimension, fl2 maxP(w).…”