This document describes how to convert a Powerpoint or any other Microsoft file to an imageformat, like JPEG, in high quality, so without using screencaptures.
First, under Windows, add a color Postscript printer, like the HP Color LaserJet 4550 PS. Use FILE: as output port. Now print any page of the document, using this printer.
Then, use Ghostscript to convert the resulting file into an image, like this:
gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=ppm -r600 -sOutputFile=outfile.ppm infile.prn
Change the resolution (600) as you wish. Instead of ppm you can also use jpeg.
