image magicでslideを切ってzipに固めるscript

crop.sh

#! /bin/bash

if [ $# -lt 1 ]; then
    echo "usage: $0 [DIR]";
    exit 1;
fi

DIR=$1;
MAX=999;

for a in $(seq 1 $MAX) ; do 
    n=$(printf %04d $a);
    if [ -f $DIR/$DIR-$n.jpg ]; then
	echo "found"
	NUM=$a;
    else
	echo "NUM : " $NUM;
	break;
    fi
done

for a in $(seq 1 $NUM) ; do 
    n=$(printf %04d $a);
    convert -rotate -90 -crop 50%x50% $DIR/$DIR-$n.jpg $DIR/crop-$n.jpg;
done

for a in $(seq 1 $NUM) ; do 
    n=$(printf %04d $a);
    i=$(printf %04d $(($a * 4 - 3)));
    j=$(printf %04d $(($a * 4 - 2)));
    k=$(printf %04d $(($a * 4 - 1)));
    l=$(printf %04d $(($a * 4)));
    mv $DIR/crop-$n-0.jpg $DIR/crop-$i.jpg;
    mv $DIR/crop-$n-1.jpg $DIR/crop-$j.jpg;
    mv $DIR/crop-$n-2.jpg $DIR/crop-$k.jpg;
    mv $DIR/crop-$n-3.jpg $DIR/crop-$l.jpg;
done
zip $DIR.zip $DIR/$DIR-*
zip $DIR-crop.zip $DIR/crop*