# File lib/tiff.rb, line 306
    def initialize(file)
      data = Data.new(file)

      @ifds = [IFD.new(data)]
      while ifd = @ifds.last.next
        break if @ifds.find{|i| i.offset == ifd.offset}
        @ifds << ifd
      end

      @jpeg_thumbnails = @ifds.map do |ifd|
        if ifd.jpeg_interchange_format && ifd.jpeg_interchange_format_length
          start, length = ifd.jpeg_interchange_format, ifd.jpeg_interchange_format_length
          data[start..(start + length)]
        end
      end.compact
    end