I have a photograph containing two objects with known dimensions. Object A, in the foreground, is 23 inches tall. Object B, in the background, is 30 inches tall. In the photograph, however, both objects appear the same height. There is no other reference of scale. Is there any way I can calculate their distances from one another with the information I have provided?
I keep feeling like there's a trig or linear algebraic equation tailor made for this, but I just cannot drag my brain into the right position. I cannot triangulate (single, static picture) but intuitively it feels as though I shouldn't NEED to. No, I do not know the focal distance from the camera to either object. The trig functions I can dredge to mind aren't helping me though; because both objects appear identical in height, I'm not getting a 180° sum in angles. Anyone? Am I missing something stupidly-obvious?
Visual representation of question
Apologies for the tags; I really am not sure what field covers this.