Recovery of the relative viewing distance of two views of an object under weak perspective projection

We show how the ratio between the viewing distances of two views of an object under weak perspective projection can be recovered. We also outline a scheme of tackling the 3-D object recognition problem based on the recovery method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>