code: def asarray(self, copy=True, cache=False, **kwargs):
          
          data = self._data
          if data is None:
              data = self._read_data(self._fh, **kwargs)
              if cache:
                  self._data = data
              else:
                  return data
          return deepcopy(data) if copy else data
docs: Return image data from file as numpy array.