convert PDF to CBZ via GhostScript, some parameters can be set (requires ghostscript, ionice, zip, jhead & imagemagick/graphicsmagick)

pdf2cbz_gs.sh

#!/bin/bash
SAVEIFS="$IFS"
IFS=$(echo -en "\n\b")

# requires ghostscript, ionice, zip, jhead & imagemagick/graphicsmagick

# do not delete temp directory with temp files
DELETE=false
# default resolution is 150 dpi
PDF_RES=150
# default JPEG qulity is 80%
JPEGQ=80


for param in "$@"
do
  if [ "$param" = "--delete" ] || [ "$param" = "-d" ]; then
    echo "config: will delete temporary files"
    DELETE=true
  elif [ "$param" = "--96dpi" ]; then
    echo "config: render PDF to 96 dpi"
    PDF_RES=96
  elif [ "$param" = "--200dpi" ]; then
    echo "config: render PDF to 200 dpi"
    PDF_RES=200
  elif [ "$param" = "--300dpi" ]; then
    echo "config: render PDF to 300 dpi"
    PDF_RES=300
  elif [ "$param" = "--help" ]; then
    echo "options [--delete] [--96dpi|--200dpi|--300dpi]"
    exit 0
  fi
done

# for all PDFs
for PDF in $(ls -1 *.pdf);
do
  echo "Working on $PDF:"
  # get filename without extension
  FILEP=${PDF%.*}
  # clean filename without spaces
  FILEPC=`echo $FILEP | sed 's| |\.|g'`
  mkdir $FILEPC

  echo " - [1/3] Extracting pages from [$PDF]"
  gs -q -dNOPAUSE -dBATCH \
     -sDEVICE=png16m \
     -r$PDF_RES \
     -dTextAlphaBits=4 -dUseCropBox \
     -sOutputFile=$FILEPC/%03d.png $PDF

  echo " - [2/3] Converting pages to JPG, quality is $JPEGQ %"
  for I in $(ls -1 $FILEPC/*.png)
  do
    convert $I -quality $JPEGQ ${I%%.png}.jpg && rm $I
  done
  jhead -purejpg -q $FILEPC/*.jpg

  CBZ=$FILEP-$PDF_RES-dpi.cbz
  echo " - [3/3] Packing to CBZ file [$CBZ]"
  ionice -c 3 find "$FILEPC/" -type f | sort | zip -j -T -9 "$CBZ" -@ > /dev/null
  if [ "$DELETE" = "true" ]; then
    rm -rf $FILEPC
  fi
  echo ""
done

IFS="$SAVEIFS"