Hi there i suggest you two add two new features.
The first one is very easy to add. It's concerning the "center" feature. (I use freetrack for racings games). When i center view i approach the mouse (sorry for my bad english). So when it's centered, i come back behing my well, so the view is far from the cockpit. By adding a timing, it's easy to push the keys and then prepare to be in the right place on our chair. Example in pictures :
For the moment :
What i would be happy to see :
The second improvement i more complex.
Sometimes when i use freetrack some things are acting like my del, for example the reflection of the steel door handle or simply a window. I would be better to delete them, possible for things who don't move.
A screen of freetrack input :
There you can see that there is some problems, to fix it i have to move the frame (or my webcam, easier :)) and hide the handle. So it could be great to ignore some pixels of the image by addind square, or better, by painting non-wanted zone :
I thank you for your great jobs, thanks free track team !