class_docstr: Class for MINC1 format images
  
  The MINC1 image class uses the default header type, rather than a specific
  MINC header type - and reads the relevant information from the MINC file on
  load.
code: def from_file_map(klass, file_map, *, mmap=True, keep_file_open=None):
      # Note that mmap and keep_file_open are included for proper
      with file_map["image"].get_prepare_fileobj() as fobj:
          minc_file = Minc1File(netcdf_file(fobj))
          affine = minc_file.get_affine()
          if affine.shape != (4, 4):
              raise MincError(
                  "Image does not have 3 spatial dimensions"
              )
          data_dtype = minc_file.get_data_dtype()
          shape = minc_file.get_data_shape()
          zooms = minc_file.get_zooms()
          header = klass.header_class(data_dtype, shape, zooms)
          data = klass.ImageArrayProxy(minc_file)
      return klass(data, affine, header, extra=None, file_map=file_map)
  
imports: from __future__ import annotations
  from numbers import Integral
  import numpy
  from .externals.netcdf import netcdf_file
  from .fileslice import canonical_slicers
  from .spatialimages import SpatialHeader, SpatialImage
label_desc: Use image node_id 1 for calling the Minc1Image obj's underlying member method code with example usage: obj.from_file_map(klass, file_map) and returns: klass