batch convert images for appstore for my project.

preprocess.rb

#!/usr/bin/env ruby
require "fileutils"
include FileUtils

p = "processed"
mkdir "processed" unless File.exists?(p)

Dir["*.png"].each do |f|
  puts "Processing #{f}."
  name = File.basename(f).split('.')[0]
  cp f, "#{p}/#{name}@2x.png"
  system("convert -resize 96x96 #{f} #{p}/#{name}[email protected]")
  system("convert -resize 64x64 #{f} #{p}/#{name}.png")
  system("convert -resize 48x48 #{f} #{p}/#{name}_small.png")
end