Converting a PDF to PNG

Question

I'm trying to convert a PDF (at least the cover of one, I'm successfully extracting the first page of the PDF with pdftk) to a PNG. I'm using imagemagick to do the converstion:

convert cover.pdf cover.png

This works, but unfortunately the cover.png comes through incorrectly rendered (some of the alpha object in the PDF aren't rendered properly). I know ImageMagick uses GhostScript to do the conversion and if I do it directly with gs I can get the desired results, but I'd rather use the convert library as it has other tools I'd like to leverage.

This command in GhostScript accomplishes the desired image:

gs -sDEVICE=pngalpha -sOutputFile=cover.png -r144 cover.pdf

I'm wondering is there any way to pass arguments through convert to GhostScript or am I stuck with calling GhostScript directly?

Answer 1

Here is a german discussion about a problem like this for SVG files where it is solved by using

convert -background transparent

Perhaps this works for you, too.