# File lib/exifr/tiff.rb, line 341
    def initialize(file)
      Data.open(file) do |data|
        @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
    end