Intro

Converting PDF to PNG is not something that ImageMagick seems to really excel in: My input was a PDF of LaTeX Beamer slides, my desired output was a sharp 1024x768 PNG file. Whatever I got out was either (ugly and) scaled (when tuning calls to convert of ImageMagick directly) or mis-sized (when tuning pixels-per-inch resolution in calls to GhostScript; ImageMagick printed that in verbose mode). If you managed to get either working well I'd be interested to hear how.

Solution

So after Googling around without too much insight I somehow felt like playing around with the Python bindings of Poppler. In the end I actually got a sharp 1024x768 PNG file out. This is what I did:

import poppler
import gtk
import urllib

input_filename = 'some-presentation.pdf'
output_filename = 'frontslide-shot.png'
width = 1024
height = 768

doc = poppler.document_new_from_file('file://%s' % \
    urllib.pathname2url(input_filename), password=None)
page = doc.get_page(0)
pixbuf = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB, True, 8,
                        width, height)
page.render_to_pixbuf(src_x=0, src_y=0,
                      src_width=width, src_height=height,
                      scale=width/page.get_size()[0],
                      rotation=0, pixbuf=pixbuf)
pixbuf.save(output_filename, 'png')