This is an old question, but as a GhostScript answer is missing and there is no hint for multipage PDF export yet I think adding another variant is ok.
gs -dBATCH -dNOPAUSE -sDEVICE=pnggray -r300 -dUseCropBox -sOutputFile=item-%03d.png examples.pdf
Options description:
dBatch and dNOPAUSE just tell gs to run in batch mode, which means
more or less it will not ask any questions. Those parameters are also
important if you want to run the command in a bash script.sDEVICE tells gs what output format to produce. pnggray is for
grayscale, png16m for 24-bit RGB color. If you insist on creating
Jpegs use -sDEVICE=jpeg to produce color JPEG files. Use the -dJPEGQ=N (N is an integer from 0 to 100, default 75)
parameter to control the Jpgeg quality.-r300 sets the scan resolution to 300dpi. If you prefer a smaller
output sizes use -r70 or if you input pdf has a high resoultion use
-r600. If you have a PDF with 300dpi and specify -r600 your images will be upscaled.-dUseCropBox tell gs to use a CropBox if defined. A CropBox is
specifies an area of interest on a page. If you have a pdf with a
large white margin and you don't want this margin on your output this
option might help.-sOutputFile defines the name(s) of the output file. The %03d.png part
tells gs to include a counter for multiple files. A two page pdf
would result in two files named item-001.png and item-002.png.- The last (unnamed parameter is the input file.)
Availability:
The convert command of imagemagick does use the gs command internally. If you can convert a pdf with imagemagick, you already have gs installed.
Install ghostscript:
RHEL:
yum install ghostscript
SLES:
zypper install ghostscript
Debian/Ubuntu:
sudo apt-get install ghostscript
Windows:
You can find Windows binaries under http://www.ghostscript.com/download/gsdnld.html
