makeIconPngs.sh

# OSX specific bash function to make icon pngs 
# for Images.xcassets/AppIcon.appiconset 
# (ie. Current XCode App icon method.)

function makeIconPngs(){
  for size in 16 32 128 256 512
  do
    retina=$(( $size * 2 ))
    sips -Z $size $1 --out icon_${size}x${size}.png
    sips -Z $retina $1 --out icon_${size}x${size}@2x.png
  done
}