Is there a way to 'auto ease' all keyframes in/out in a project?

I've used a LOT of keyframes to do nice 'Ken Burns' style pans/zooms on photos in a project, and now having done them all I'd really like to quickly/easily make them all into 'ease in'/'ease out' keyframes to make the transitions a bit smoother.

It doesn't seem, however, like there's an easy way to achieve this after the fact, or even a menu toggle to make 'ease in'/'ease out' the default...

Anybody know of an easy way to do this? OR even just an easier way to do a nice Ken Burns pan/zoom on MULTIPLE photos within the timeline??