for i in *.tif; tiff2pdf -j -o $i.pdf $i
pdftk *.pdf cat output result.pdf

#!/bin/bash
#
# any2djvu-bw
#

if [ -z `which anytopnm` -o -z `which ppmtopgm` -o -z `which pgmtopbm`\
    -o -z `which cjb2` ]; then
  usage
  echo "Error: anytopnm, ppmtopgm, pgmtopbm and cjb2 are needed"
  echo
  exit 1
fi

shopt -s extglob

DEFMASK=*.tif
# uncomment the following line to compile a bundled DjVu document
OUTFILE="result.djvu"

function usage() {
  echo
  echo "usage:"
  echo
  echo "$0 [\"REGEXP\"]"
  echo "    converts single pages with the default mask $DEFMASK (or REGEXP if provided)"
  echo "    in the current directory to single-page black and white djvu documents"
# uncomment the following line to compile a bundled DjVu document
 echo "    and bundles them as a djvu file $OUTFILE"
  echo
}

if [ -n "$1" ]; then
  MASK=$1
else
  MASK=$DEFMASK
fi

for i in $MASK; do
  if [ ! -e "$i" ]; then
    usage
    echo "Error: current directory must contain files with the mask $MASK"
    echo
    exit 1
  fi
  export base="${i%.*}"
  if cjb2 "$i" "$base.djvu" &> /dev/null; then
      echo "$i"
  else
      anytopnm "$i" | ppmtopgm | pgmtopbm -value 0.450 > "$i.pbm"
      cjb2 "$i.pbm" "$i.djvu"
      echo "$i: Converted to bitonal"
      rm -f "$i.pbm"
  fi
  # echo $base
done

djvm -c $OUTFILE *.djvu