backward compatible EnsureType

[wyli]

Is your feature request related to a problem? Please describe.
the current EnsureType removes any metadata

MONAI/monai/transforms/utility/array.py

Line 464 in 99b9dd7

output_type = torch.Tensor if self.data_type == "tensor" else np.ndarray

given it's extensively used in the existing tutorials, would be great to enable metatensor output support and remove the inverse to preserve metadata when inverting the transform.

MONAI/monai/transforms/utility/dictionary.py

Lines 570 to 574 in 99b9dd7

	# FIXME: currently, only convert tensor data to numpy array or scalar number,
	# need to also invert numpy array but it's not easy to determine the previous data type
	d[key] = convert_to_numpy(d[key])
	# Remove the applied transform
	self.pop_transform(d, key)

[Nic-Ma]

Hi @wyli ,

Thanks for raising this ticket.
@KumoLiu and I also see this issue when updating the tutorials, I think maybe we can just change the default value of data_type arg to data_type: str = "metatensor" instead of "tensor"?

Thanks.

[wyli]

sure @Nic-Ma, I'm working on a fix for this one.