Sample helper script to create images generated by dragging pixelmator's layers to finder from @2x resolution to normal resolution and facilitates its use in iOS projects

using_imagemagick_convert_to_generate_half_size_images.rb

# Add ...@2x.png string end to those exported using Pixelmator
Dir.glob("./*2x.png").each do |old_path|
  next if old_path =~ /@2x.png/
  
  ext = File.extname(old_path)
  filename = File.basename(old_path, ext)
  new_filename = filename.sub("2x", "@2x") + ext
  
  File.rename(old_path, new_filename)
end

# Use image magick to generate hald sized images
Dir.glob("./*@2x.png").each do |full_image|
  half_image = full_image.sub("@2x", "")
  system "convert #{full_image} -resize 50% #{half_image}"
end