#!/bin/sh
# subjpeg - dark frame removal from digital camera images
# (c) Alec Muffett, 2000
# contact: alecm

if [ $# -lt 2 ]
then
    echo "Usage: $0 darkframe.jpg file1.jpg file2.jpg ..." 1>&2
    exit 1
fi

DF=tmpdf.$$.pnm
DJPEG="djpeg -dct float -dither none -pnm -verbose"

set -x

$DJPEG $1 > $DF
shift

for IMAGE in "$@"
do
    NAME=`basename $IMAGE .jpg`
    $DJPEG $IMAGE > $NAME.pnm
    pnminvert $NAME.pnm > $NAME-inv.pnm
    pnmarith -subtract $NAME.pnm $DF > $NAME-df.pnm
    pnminvert $NAME-df.pnm > $NAME-df-inv.pnm

    rm $NAME.pnm $NAME-inv.pnm
done

rm $DF

set +x

exit 0