any2djvu-bw.sh

#!/bin/bash
#
# >> any2djvu-bw.sh <<
#

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="*.jpg"
DEFMASK="*.jpg"
DPI=150
# uncomment the following line to compile a bundled DjVu document
OUTFILE="#0-bw.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
if [ ! -e $i.djvu ]; then
echo "$i"
anytopnm $i | ppmtopgm | pgmtopbm -value 0.499 > $i.pbm
# in netpbm >= 10.23 the above line can be replaced with the following:
# anytopnm $i | ppmtopgm | pamditherbw -value 0.499 > $.pbm
cjb2 -dpi $DPI $i.pbm $i.djvu
rm -f $i.pbm
fi
done

# uncomment the following line to compile a bundled DjVu document
djvm -c $OUTFILE $MASK.djvu