parallel imagemagick command:
PAGES=18
for PADNUM in $(seq -f "%04g" 0 $((PAGES-1))); do
NUM=$((PADNUM))
convert -density 150 "comic-dk.pdf[$NUM]" -quality 00 dk_panel${PADNUM}.png &
done
Higher resolution versions could be made with density set to e.g. 300 and the
quality parameter for PNG convert is explained on:
https://stackoverflow.com/questions/9710118/convert-multipage-pdf-to-png-and-back-linux
