#!/bin/bash                                                                                                                                                                       
# Scales a jpeg image provided in the first argument and stores it in the second argument.                                                                                        # If provided, the third and fourth arguments indicate (x,y) size in pixels.                                                                                                      

xsize=100
ysize=150

if [ $# != 2 ] && [ $# != 4 ]
then
    echo "need two or four arguments"
    exit 1
fi

if [ $# == 4 ]
then
    xsize=$3
    ysize=$4
fi

djpeg < $1 | pamscale -xysize $xsize $ysize | cjpeg > $2