Convert pdf to jpg

This command will convert all .pdf files in a directory into a 800px (wide or height, whichever is smaller) image (with the aspect ratio kept) .jpg.

for file in `ls *.pdf`; do convert -verbose -colorspace RGB -resize 800 -interlace none \
 -density 300 -quality 80 $file `echo $file | sed 's/\.pdf$/\.jpg/'`; done

http://www.shell-fu.org/lister.php?id=627