The inverse projection problem is

using upside$-$down images to generate three$-$dimensional images.

difficulty in determining three$-$dimensional objects from a given two$-$dimensional representation.

due to retinal inversion of light.

the turning of two$-$dimensional images upside$-$down to give a different perception of a three$-$dimensional reconstruction.

using three$-$dimensional objects to generate two$-$dimensional images.