# File lib/exifr/tiff.rb, line 415
    def gps
      return nil unless gps_latitude && gps_longitude
      GPS.new(gps_latitude.to_f * (gps_latitude_ref == 'S' ? -1 : 1),
              gps_longitude.to_f * (gps_longitude_ref == 'W' ? -1 : 1),
              gps_altitude && (gps_altitude.to_f * (gps_altitude_ref == "\1" ? -1 : 1)),
              gps_img_direction && gps_img_direction.to_f)
    end