Does anyone know how I can warp a photo of a sheet of paper taken for perpas 20-3 feet (with significant persepctive distortion) into a “orthographic” projection taht essentially looks like page scanned on a flatbed scanner?
I have a camera but no scanner and need to make some copies in a pinch using it and my printer 
the distortion is merely an annoyance butn Itr’d be the bees knees if I could correct for it.
don’t know if it will work for a single image, but basicly Huggin the panorama generator tool has this kind of capability (for photostiching) its free. you will need to know the camera lens size i believe or you could guess that kind of stuff.
the other way is to UV map the page to a grid in blender. 
if you can get the same angle photo (exactly) every time, then the blender method could be very very quick.
Alltaken
Have you tried using the perspective tool in The Gimp?
http://www.bethelks.edu/bstucky/gimp/perspective_correct/
This should do the trick.
–
Brian