pdf2zip.sh

#!/bin/bash

pdf2zip(){
  file_path="$1"
  file_name="${file_path##*/}"
  name="${file_name%.pdf}"
  extension="${file_path##*.}"

  if [ "${extension}" != "pdf" ]
  then
   echo "${file_path} is not PDF...."
   return 0
  fi

  echo "${file_name} is PDF!! convert..."
  mkdir "${name}" > /dev/null
  gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=jpeg -r300 -sOutputFile="${name}"/\%003d.jpg "${file_path}" > /dev/null
  zip -r "${name}.zip" "${name}/" > /dev/null
  rm -rf "${name}" > /dev/null
}

for arg in "$@"
do
  pdf2zip "${arg}"
done

使い方
find . -print0 | xargs -0 -n 1 ./pdf2zip.sh
だいたいこんなん。