Resize images and use the tileup gem to slice them up for a slippy map

resizeit.sh

imagename=$1
imagebasename=${imagename%.*}

size=512

for size in 512 1024 2048 4096 8192 16384
do
  echo "Resizing to ${size}x${size}"
  convert -size ${size}x${size} xc:transparent canvas.png
  time composite -resize ${size}x${size} $1 -gravity center canvas.png -size ${size}x${size} "${imagebasename}-${size}.png"
  ls -ltrh ${imagebasename}-${size}.png
  time tileup --in="${imagebasename}-${size}.png" --output-dir=$size
  rm "${imagebasename}-${size}.png"
done

mv 512 1
mv 1024 2
mv 2048 3
mv 4096 4
mv 8192 5
mv 16384 6