I have an image of a wall taken from a phone camera from a known height h from the ground.
Assume that the camera was held perfectly parallel to the wall and that the bottom of the image is perfectly aligned with the bottom of the wall.
Is there a way to find out the point in the image that corresponds to the height h ? (i.e if I drew an imaginary line (that's parallel to the ground) from the camera lens to the wall, at what point would the intersection of the line on the wall show up in the image ?
I know the focal length of the camera, if that helps.