Crop foo for double-spread comic scans

half.sh

#!/bin/sh
FILE=$1
echo $FILE
WIDTH=$(identify $FILE | awk '{print $3}' | awk -F x '{print $1}')
HEIGHT=$(identify $FILE | awk '{print $3}' | awk -F x '{print $2}')
HALFWIDTH=$(expr $WIDTH / 2)
LEFT=$(echo $FILE | sed 's/.jpg$/.l.jpg/i')
RIGHT=$(echo $FILE | sed 's/.jpg$/.r.jpg/i')
convert $FILE -crop "${HALFWIDTH}x${HEIGHT}+0x0" $LEFT
convert $FILE -crop "${HALFWIDTH}x${HEIGHT}+${HALFWIDTH}x0" $RIGHT