# File lib/paperclip/thumbnail.rb, line 89
    def transformation_command
      scale, crop = @current_geometry.transformation_to(@target_geometry, crop?)
      trans = []
      trans << "-coalesce" if animated?
      trans << "-resize" << %["#{scale}"] unless scale.nil? || scale.empty?
      trans << "-crop" << %["#{crop}"] << "+repage" if crop
      trans
    end