如何使用快速图像调整图像大小？

Question

我在Ruby上使用FastImage来调整一些图像的大小： https://github.com/sdsykes/fastimage_resize/blob/master/test/test.rb

这是我的代码，所以我从昨天开始就遇到了这个错误：

class IconExport


  def initialize(img_url,target_directory,tab)
    @img_url=img_url
    @target = target_directory
    @tab = tab
  end



  def export

              @tab.each do |fn, info|
              puts"#{fn} ,#{info}"
              outfile = File.join(@target, "fixtures", "resized_" + fn)
              puts "#{outfile}"
              puts "#{info[1][0] / 3}"
              FastImage.resize(@img_url + fn, info[1][0] / 3, info[1][1] / 2, :outfile=>outfile)
              assert_equal [info[1][0] / 3, info[1][1] / 2], FastImage.size(outfile)
              File.unlink outfile

                      end
    end


end

错误：

icon2.rb:59:in `block in export': uninitialized constant IconExport::FastImage (NameError)
    from icon2.rb:54:in `each'
    from icon2.rb:54:in `export'
    from icon2.rb:82:in `<main>'

请帮帮我！