Convert image asset to Android *dpi versions

gistfile1.rb

require "pathname"
require "fileutils"

original = "{query}"
original_path = Pathname(original)


command = "sips -g pixelWidth #{original}"
output = `#{command}`
size = output.split("\n").last.split(/\s/).last.to_i

variants = {"mdpi" => 0.75*size,"xhdpi" => 1.5*size,"xxhdpi" => 2.0*size}

base_path = original_path.dirname.realpath
filename = original_path.basename

variants.each {|name, size|
  d = base_path + "drawable-#{name}"
  d.mkpath
  new_file_name = (d + filename).to_s
  command = "sips --resampleWidth #{size.to_i} #{original} --out #{new_file_name}"
  `#{command}`
}