> I often do `ps2pdf downloaded.pdf test.pdf', yes, input is > PDF, not PostScript,
ps2pdf is essentially "gs -sDEVICE=pdfwrite", and since ghostscript understands both Postscript and PDF it is indeed possible to feed PDF to ps2pdf, despite the name. > to see if test.pdf comes out smaller than downloaded.pdf if > I'm intending to keep it. Sometimes the savings are large. If you're using the default settings then my guess is that ps2pdf achieves these savings by recompressing images to JPEG in lower quality, or even downsampling images to lower resolution. So you're paying for the smaller file size with a loss in quality. > I wonder if I'm rastering the fonts when doing this. Probably not, and that's the funny thing. Analogously to ps2pdf, pstops is "gs -sDEVICE=pswrite", but while the pdfwrite device seems to handle fonts correctly, pswrite converts text to bitmap images (or curves, if the font size is large). However... (doing some googling)... It turns out there's a new ghostscript device "ps2write" (and a corresponding "ps2ps2" script) that *does* preserve fonts. My guess is that this device is handled internally the same as pdfwrite, since the output syntax is very PDF-like. Nevertheless, for hacking the Postscript file (e.g., to extract figures, if you don't have the source) the output from this device is still much more cumbersome than the output produced directly by grops (or any other program which generates clean, editable Postscript).
