1 #!/bin/sh -ex

     2 

     3 # $1 file.pnm

     4 # 600 dpi by default.

     5 

     6 INPUT=$1

     7 DPI=190

     8 OUTPUT=`basename $INPUT .pgm`.djvu

     9 TMPFILE=/tmp/tempfile

    10 

    11 function threshold_mkbitmap

    12 {

    13 PPM=$1

    14 PBM=$2

    15 mkbitmap -s 1 -o "$PBM" "$PPM"

    16 }

    17 

    18 function threshold_netpbm

    19 {

    20 pamditherbw -threshold $1 | pamtopnm >$2

    21 

    22 }

    23 

    24 function threshold_netpbm2

    25 {

    26 pamthreshold -contrast 0.5 -dual=16x16  $1 |pamtopnm > $2

    27 

    28 }

    29 

    30 if [ $# -ne 1 ]; then

    31 	echo "usage: $0 <file.pnm>"

    32 	exit

    33 fi

    34 

    35 pnmnorm < "$INPUT" > "$TMPFILE.ppm"

    36 threshold_netpbm2 "$TMPFILE.ppm" "$TMPFILE.pbm"

    37 

    38 cjb2 -clean -dpi $DPI "$TMPFILE.pbm" "$TMPFILE.djvu"

    39 

    40 djvumake "$OUTPUT" PPM="$TMPFILE.ppm" Sjbz="$TMPFILE.djvu"

    41 

    42 rm -f "$TMPFILE.pbm"

    43 rm -f "$TMPFILE.ppm"

    44 rm -f "$TMPFILE.djvu"

    45 echo Done: \"$OUTPUT\" created.