Jim,
We might both find it useful to chat. Can you email me your Skype id?
My email is edmundronald at gmail dot com
BTW, you might find it useful to save out and read in the F-transformed image file and kernels. You don't need to recompute them unless they change. I don't know if that is useful at your image size, but it might be worth testing.
I think Matlab has the ability to save out any variable, and the whole environment.
Edmund