Two-view metrology deals with two projections of the same scene from different projection centers, and .

Because the transformation from to and to are homographies, going from to is a homography as well. Specifically, for in the left image, in the right image, and in the scene plane, we have the following:

Zooming

A trivial case of two views is zooming. With

we have

Vanishing Points

If we have two views, our vanishing points are only related by camera intrinsics and rotation, not by translation. Formally, we have the following:

Note that this can be applied to the two other vanishing points as well.