def _test_numpy(dtype_name, nchannels, order='c'):
np_img = create_numpy_image(dtype_name, nchannels, order)
img_container = ImageContainer(Image(np_img))
recast = img_container.asarray()
# asarray always returns 3 channels
np_img = np.atleast_3d(np_img)
vital_img = img_container.image()
pixel_type_name = vital_img.pixel_type_name()
pixel_type_name = vital_img.pixel_type_name()
want = map_dtype_name_to_pixel_type(dtype_name)
assert pixel_type_name == want, 'want={} but got={}'.format(
want, pixel_type_name)
if not np.all(np_img == recast):
raise AssertionError(
'Failed dtype={}, nchannels={}, order={}'.format(
dtype_name, nchannels, order))
