create 500mb tiff image with random contents.

gistfile1.sh

#!/bin/sh
size=9348
count=10
tmpname="500mb.tiff"
for i in `jot - 1 $count`; do
    convert -size ${size}x${size} xc: +noise Random $tmpname
    ofname=`md5 -q $tmpname`'.tiff'
    mv $tmpname $ofname
done