Zoom & Full Size image perimssion

Hi,
i'm new to G2 Forum so
i'm sorry if i'm posting in the wrong section.

I'm using gallery 2.3.1 in a project, and i need to let anonymous users to see
resized images but not the original(full size) one.
My problem is that the anonymous user need to use the Zoom but MagicZoom doesn't work if you have not the permission to see full size.
So I'm wondering if there's a way to
let the MagicZoom module show the "zoom thumb" when the full size is blocked?

thank you

ric