Using ImageMagick or Ghostscript (or something) to scale PDF to fit page?

Question

I've been bashing my head against this to no avail.

I need to shrink some large PDFs to print on an 8.5x11 inch (standard letter) page. Can ImageMagick/Ghostscript handle this sort of thing, or am I having so much trouble because I'm using the wrong tool for the job?

Just relying on the 'shrink to page' option in client-side print dialogs is not an option, as we'd like for this to be easy-to-use for the end users.

Answer 1

The problem with using ImageMagick is that you are converting to a raster image format, increasing file size and decreasing quality for any vector elements on your pages.

Multivalent will retain the vector information of the PDF. Try:

java -cp Multivalent.jar tool.pdf.Impose -dim 1x1 -paper "8.5x11in" myFile.pdf

to create an output file myFile-up.pdf

Answer 2

I would not use convert. It uses Ghostscript in the background, but is much slower. I'd use Ghostscript directly, since it gives me much more direct control (and also some control over settings which are much more difficult to achieve with convert). And for convert to work for PDF-to-PDF conversion you'll have Ghostscript installed anyway:

  gs \
    -o /path/to/resized.pdf \
    -sDEVICE=pdfwrite \
    -dPDFFitPage \
    -r300x300 \
    -g2550x3300 \
    /path/to/original.pdf

Answer 3

ImageMagick's mogrify/convert commands will indeed do the job. Stephen Page had just about the right idea, but you do need to set the dpi of the file as well, or you won't get the job done.

Assuming you have a file that's 300 dpi and already the same aspect ratio as 8.5 x 11 the command would be:

// 300dpi x 8.5 -2550, 300dpi x 11 -3300
convert original.pdf -density "300" -resize "2550x3300" resized.pdf

If the aspect ratio is different, then you need to do some slightly trickier cropping.

Answer 4

The Ghostscript approach worked well for me. (I moved my file from my Windows PC to a Linux computer and ran it there.) I made one small change to the Ghostscript command because the Ghostscript resize command above completely fills an 8.5 by 11 inch page. My printer cannot print to the edge, though, so several milllimeters along each page edge were lost. To overcome that problem, I scaled my PDF document to 0.92 of a full 8.5 by 11 inches. That way I saw everything centered on the page and had a slight margin. Because 0.92 * (2550x3300) = (2346x3036), I ran the following Ghostscript command:

  gs -sDEVICE=pdfwrite \
     -dPDFFitPage \
     -r300x300 \
     -g2346x3036 \
     /home/user/path/original.pdf \
     -o /home/user/path/resized.pdf