ibFrom(ifX + 2, ifY + 1)
            b4 = bDibFrom(ifX + 3, ifY + 1): g4 = bDibFrom(ifX + 4, ifY + 1):
             r4 = bDibFrom(ifX + 5, ifY + 1)
            
            ' Interplate in x direction:
            ir1 = r1 * (1 - dy) + r3 * dy: ig1 = g1 * (1 - dy) + g3 * dy: ib1 =
             b1 * (1 - dy) + b3 * dy
            ir2 = r2 * (1 - dy) + r4 * dy: ig2 = g2 * (1 - dy) + g4 * dy: ib2 =
             b2 * (1 - dy) + b4 * dy
            ' Interpolate in y:
            r = ir1 * (1 - dX) + ir2 * dX: g