def __init__(self, image_file):
    '''Initialise the image structure from the given file, including a
    proper model of the experiment.'''

    assert(self.understand(image_file))

    FormatSMVADSCNoDateStamp.__init__(self, image_file)

    return
  def understand(image_file):
    '''Check to see if this is ADSC SN 457.'''

    # check this is detector serial number 457

    size, header = FormatSMVADSCNoDateStamp.get_smv_header(image_file)

    if int(header['DETECTOR_SN']) != 457:
      return False

    return True