gistfile1.rb

  # Use spawn to fork the resize.
  # you'll want to have the following lines in environment.rb:
  #   Spawn::method :fork, 'production'
  #   Spawn::method :yield, 'test'
  def downsample!(quality=DEFAULT_QUALITY)
    id = spawn do
      image = Magick::ImageList.new(self.absolute_filename)
      image.write("jpeg:#{self.absolute_filename}") {self.quality = quality}
    end
    wait(id)
  end