Videoprojector distorsion

I have applied a wide-angle lens to a videoprojector to increase the greatness of the projection without getting further too much me.
but the projection is deformed as in the figure under.

how can I correct the exit of the renderer so that to correct the distorsion?

maybe this quickhack helps.

map the texture onto a part of a sphere might be more correct though… (2.3 kB)

just what served me, thanks thousand.