Automatically move large images in fullscreen

[Dreamer]

I have a suggestion, but I'm not sure if I can explain it sufficiently, so

if anyone knows what I mean, please try to explain it.

Automatically move large (or enlarged) images in fullscreen (and viewer)

with LMB and move...

- press and hold LMB
- move a bit
- while moving, release LMB
= image should be moved automatically then
= speed of moving should depends on the firs move while holding LMB

I saw it in some program or game, hope someone can explain it better...