4636 4637 backward compatible types (#4638)

Signed-off-by: Wenqi Li <[email protected]>

monai/data/meta_tensor.py

@@ -15,13 +15,15 @@
 from copy import deepcopy
 from typing import Any, Sequence
 
+import numpy as np
 import torch
 
 from monai.config.type_definitions import NdarrayTensor
 from monai.data.meta_obj import MetaObj, get_track_meta
 from monai.data.utils import affine_to_spacing, decollate_batch, list_data_collate, remove_extra_metadata
+from monai.utils import look_up_option
 from monai.utils.enums import PostFix
-from monai.utils.type_conversion import convert_to_tensor
+from monai.utils.type_conversion import convert_data_type, convert_to_tensor
 
 __all__ = ["MetaTensor"]
 
@@ -307,6 +309,33 @@ def as_dict(self, key: str) -> dict:
             PostFix.transforms(key): deepcopy(self.applied_operations),
         }
 
+    def astype(self, dtype, device=None, *unused_args, **unused_kwargs):
+        """
+        Cast to ``dtype``, sharing data whenever possible.
+
+        Args:
+            dtype: dtypes such as np.float32, torch.float, "np.float32", float.
+            device: the device if `dtype` is a torch data type.
+            unused_args: additional args (currently unused).
+            unused_kwargs: additional kwargs (currently unused).
+
+        Returns:
+            data array instance
+        """
+        if isinstance(dtype, str):
+            mod_str, *dtype = dtype.split(".", 1)
+            dtype = mod_str if not dtype else dtype[0]
+        else:
+            mod_str = getattr(dtype, "__module__", "torch")
+        mod_str = look_up_option(mod_str, {"torch", "numpy", "np"}, default="numpy")
+        if mod_str == "torch":
+            out_type = torch.Tensor
+        elif mod_str in ("numpy", "np"):
+            out_type = np.ndarray
+        else:
+            out_type = None
+        return convert_data_type(self, output_type=out_type, device=device, dtype=dtype, wrap_sequence=True)[0]
+
     @property
     def affine(self) -> torch.Tensor:
         """Get the affine."""
@@ -334,7 +363,7 @@ def new_empty(self, size, dtype=None, device=None, requires_grad=False):
         )
 
     @staticmethod
-    def ensure_torch_and_prune_meta(im: NdarrayTensor, meta: dict):
+    def ensure_torch_and_prune_meta(im: NdarrayTensor, meta: dict, simple_keys: bool = False):
         """
         Convert the image to `torch.Tensor`. If `affine` is in the `meta` dictionary,
         convert that to `torch.Tensor`, too. Remove any superfluous metadata.
@@ -353,12 +382,12 @@ def ensure_torch_and_prune_meta(im: NdarrayTensor, meta: dict):
         if not get_track_meta() or meta is None:
             return img
 
-        # ensure affine is of type `torch.Tensor`
-        if "affine" in meta:
-            meta["affine"] = convert_to_tensor(meta["affine"])
-
         # remove any superfluous metadata.
-        remove_extra_metadata(meta)
+        if simple_keys:
+            # ensure affine is of type `torch.Tensor`
+            if "affine" in meta:
+                meta["affine"] = convert_to_tensor(meta["affine"])  # bc-breaking
+            remove_extra_metadata(meta)  # bc-breaking
 
         # return the `MetaTensor`
         return MetaTensor(img, meta=meta)

monai/transforms/io/array.py

@@ -108,9 +108,10 @@ class LoadImage(Transform):
     def __init__(
         self,
         reader=None,
-        image_only: bool = True,
+        image_only: bool = False,
         dtype: DtypeLike = np.float32,
         ensure_channel_first: bool = False,
+        simple_keys: bool = False,
         *args,
         **kwargs,
     ) -> None:
@@ -127,6 +128,7 @@ def __init__(
             dtype: if not None convert the loaded image to this data type.
             ensure_channel_first: if `True` and loaded both image array and metadata, automatically convert
                 the image array shape to `channel first`. default to `False`.
+            simple_keys: whether to remove redundant metadata keys, default to False for backward compatibility.
             args: additional parameters for reader if providing a reader name.
             kwargs: additional parameters for reader if providing a reader name.
 
@@ -145,6 +147,7 @@ def __init__(
         self.image_only = image_only
         self.dtype = dtype
         self.ensure_channel_first = ensure_channel_first
+        self.simple_keys = simple_keys
 
         self.readers: List[ImageReader] = []
         for r in SUPPORTED_READERS:  # set predefined readers as default
@@ -255,7 +258,7 @@ def __call__(self, filename: Union[Sequence[PathLike], PathLike], reader: Option
         meta_data = switch_endianness(meta_data, "<")
 
         meta_data[Key.FILENAME_OR_OBJ] = f"{ensure_tuple(filename)[0]}"  # Path obj should be strings for data loader
-        img = MetaTensor.ensure_torch_and_prune_meta(img_array, meta_data)
+        img = MetaTensor.ensure_torch_and_prune_meta(img_array, meta_data, self.simple_keys)
         if self.ensure_channel_first:
             img = EnsureChannelFirst()(img)
         if self.image_only:

monai/transforms/io/dictionary.py

@@ -72,8 +72,9 @@ def __init__(
         meta_keys: Optional[KeysCollection] = None,
         meta_key_postfix: str = DEFAULT_POST_FIX,
         overwriting: bool = False,
-        image_only: bool = True,
+        image_only: bool = False,
         ensure_channel_first: bool = False,
+        simple_keys: bool = False,
         allow_missing_keys: bool = False,
         *args,
         **kwargs,
@@ -103,12 +104,13 @@ def __init__(
                 dictionary containing image data array and header dict per input key.
             ensure_channel_first: if `True` and loaded both image array and metadata, automatically convert
                 the image array shape to `channel first`. default to `False`.
+            simple_keys: whether to remove redundant metadata keys, default to False for backward compatibility.
             allow_missing_keys: don't raise exception if key is missing.
             args: additional parameters for reader if providing a reader name.
             kwargs: additional parameters for reader if providing a reader name.
         """
         super().__init__(keys, allow_missing_keys)
-        self._loader = LoadImage(reader, image_only, dtype, ensure_channel_first, *args, **kwargs)
+        self._loader = LoadImage(reader, image_only, dtype, ensure_channel_first, simple_keys, *args, **kwargs)
         if not isinstance(meta_key_postfix, str):
             raise TypeError(f"meta_key_postfix must be a str but is {type(meta_key_postfix).__name__}.")
         self.meta_keys = ensure_tuple_rep(None, len(self.keys)) if meta_keys is None else ensure_tuple(meta_keys)

monai/transforms/utility/array.py

@@ -435,6 +435,8 @@ class EnsureType(Transform):
         device: for Tensor data type, specify the target device.
         wrap_sequence: if `False`, then lists will recursively call this function, default to `True`.
             E.g., if `False`, `[1, 2]` -> `[tensor(1), tensor(2)]`, if `True`, then `[1, 2]` -> `tensor([1, 2])`.
+        track_meta: whether to convert to `MetaTensor` when `data_type` is "tensor".
+            If False, the output data type will be `torch.Tensor`. Default to the return value of ``get_track_meta``.
 
     """
 
@@ -446,11 +448,13 @@ def __init__(
         dtype: Optional[Union[DtypeLike, torch.dtype]] = None,
         device: Optional[torch.device] = None,
         wrap_sequence: bool = True,
+        track_meta: Optional[bool] = None,
     ) -> None:
         self.data_type = look_up_option(data_type.lower(), {"tensor", "numpy"})
         self.dtype = dtype
         self.device = device
         self.wrap_sequence = wrap_sequence
+        self.track_meta = get_track_meta() if track_meta is None else bool(track_meta)
 
     def __call__(self, data: NdarrayOrTensor):
         """
@@ -461,10 +465,17 @@ def __call__(self, data: NdarrayOrTensor):
                 if applicable and `wrap_sequence=False`.
 
         """
-        output_type = torch.Tensor if self.data_type == "tensor" else np.ndarray
+        if self.data_type == "tensor":
+            output_type = MetaTensor if self.track_meta else torch.Tensor
+        else:
+            output_type = np.ndarray  # type: ignore
         out: NdarrayOrTensor
         out, *_ = convert_data_type(
-            data=data, output_type=output_type, dtype=self.dtype, device=self.device, wrap_sequence=self.wrap_sequence
+            data=data,
+            output_type=output_type,  # type: ignore
+            dtype=self.dtype,
+            device=self.device,
+            wrap_sequence=self.wrap_sequence,
         )
         return out
 

monai/transforms/utility/dictionary.py

@@ -62,7 +62,7 @@
 )
 from monai.transforms.utils import extreme_points_to_image, get_extreme_points
 from monai.transforms.utils_pytorch_numpy_unification import concatenate
-from monai.utils import convert_to_numpy, deprecated, deprecated_arg, ensure_tuple, ensure_tuple_rep
+from monai.utils import deprecated, deprecated_arg, ensure_tuple, ensure_tuple_rep
 from monai.utils.enums import PostFix, TraceKeys, TransformBackends
 from monai.utils.type_conversion import convert_to_dst_type
 
@@ -519,7 +519,7 @@ def inverse(self, data: Mapping[Hashable, NdarrayOrTensor]) -> Dict[Hashable, Nd
         return d
 
 
-class EnsureTyped(MapTransform, InvertibleTransform):
+class EnsureTyped(MapTransform):
     """
     Dictionary-based wrapper of :py:class:`monai.transforms.EnsureType`.
 
@@ -541,6 +541,7 @@ def __init__(
         dtype: Union[DtypeLike, torch.dtype] = None,
         device: Optional[torch.device] = None,
         wrap_sequence: bool = True,
+        track_meta: Optional[bool] = None,
         allow_missing_keys: bool = False,
     ) -> None:
         """
@@ -552,28 +553,21 @@ def __init__(
             device: for Tensor data type, specify the target device.
             wrap_sequence: if `False`, then lists will recursively call this function, default to `True`.
                 E.g., if `False`, `[1, 2]` -> `[tensor(1), tensor(2)]`, if `True`, then `[1, 2]` -> `tensor([1, 2])`.
+            track_meta: whether to convert to `MetaTensor` when `data_type` is "tensor".
+                If False, the output data type will be `torch.Tensor`. Default to the return value of `get_track_meta`.
             allow_missing_keys: don't raise exception if key is missing.
         """
         super().__init__(keys, allow_missing_keys)
-        self.converter = EnsureType(data_type=data_type, dtype=dtype, device=device, wrap_sequence=wrap_sequence)
+        self.converter = EnsureType(
+            data_type=data_type, dtype=dtype, device=device, wrap_sequence=wrap_sequence, track_meta=track_meta
+        )
 
     def __call__(self, data: Mapping[Hashable, NdarrayOrTensor]) -> Dict[Hashable, NdarrayOrTensor]:
         d = dict(data)
         for key in self.key_iterator(d):
-            self.push_transform(d, key)
             d[key] = self.converter(d[key])
         return d
 
-    def inverse(self, data: Mapping[Hashable, Any]) -> Dict[Hashable, Any]:
-        d = deepcopy(dict(data))
-        for key in self.key_iterator(d):
-            # 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)
-        return d
-
 
 class ToNumpyd(MapTransform):
     """

monai/utils/type_conversion.py

@@ -172,7 +172,7 @@ def convert_to_numpy(data, dtype: DtypeLike = None, wrap_sequence: bool = False)
             E.g., `[1, 2]` -> `[array(1), array(2)]`. If `True`, then `[1, 2]` -> `array([1, 2])`.
     """
     if isinstance(data, torch.Tensor):
-        data = data.detach().to(dtype=get_equivalent_dtype(dtype, torch.Tensor), device="cpu").numpy()
+        data = np.asarray(data.detach().to(device="cpu").numpy(), dtype=get_equivalent_dtype(dtype, np.ndarray))
     elif has_cp and isinstance(data, cp_ndarray):
         data = cp.asnumpy(data).astype(dtype, copy=False)
     elif isinstance(data, (np.ndarray, float, int, bool)):
@@ -235,12 +235,13 @@ def convert_data_type(
     wrap_sequence: bool = False,
 ) -> Tuple[NdarrayTensor, type, Optional[torch.device]]:
     """
-    Convert to `torch.Tensor`/`np.ndarray` from `torch.Tensor`/`np.ndarray`/`float`/`int` etc.
+    Convert to `MetaTensor`, `torch.Tensor` or `np.ndarray` from `MetaTensor`, `torch.Tensor`,
+    `np.ndarray`, `float`, `int`, etc.
 
     Args:
         data: data to be converted
-        output_type: `torch.Tensor` or `np.ndarray` (if `None`, unchanged)
-        device: if output is `torch.Tensor`, select device (if `None`, unchanged)
+        output_type: `monai.data.MetaTensor`, `torch.Tensor`, or `np.ndarray` (if `None`, unchanged)
+        device: if output is `MetaTensor` or `torch.Tensor`, select device (if `None`, unchanged)
         dtype: dtype of output data. Converted to correct library type (e.g.,
             `np.float32` is converted to `torch.float32` if output type is `torch.Tensor`).
             If left blank, it remains unchanged.

tests/test_arraydataset.py

@@ -23,15 +23,15 @@
 from monai.transforms import AddChannel, Compose, LoadImage, RandAdjustContrast, RandGaussianNoise, Spacing
 
 TEST_CASE_1 = [
-    Compose([LoadImage(), AddChannel(), RandGaussianNoise(prob=1.0)]),
-    Compose([LoadImage(), AddChannel(), RandGaussianNoise(prob=1.0)]),
+    Compose([LoadImage(image_only=True), AddChannel(), RandGaussianNoise(prob=1.0)]),
+    Compose([LoadImage(image_only=True), AddChannel(), RandGaussianNoise(prob=1.0)]),
     (0, 1),
     (1, 128, 128, 128),
 ]
 
 TEST_CASE_2 = [
-    Compose([LoadImage(), AddChannel(), RandAdjustContrast(prob=1.0)]),
-    Compose([LoadImage(), AddChannel(), RandAdjustContrast(prob=1.0)]),
+    Compose([LoadImage(image_only=True), AddChannel(), RandAdjustContrast(prob=1.0)]),
+    Compose([LoadImage(image_only=True), AddChannel(), RandAdjustContrast(prob=1.0)]),
     (0, 1),
     (1, 128, 128, 128),
 ]
@@ -48,13 +48,13 @@ def __call__(self, input_):
 
 
 TEST_CASE_3 = [
-    TestCompose([LoadImage(), AddChannel(), Spacing(pixdim=(2, 2, 4)), RandAdjustContrast(prob=1.0)]),
-    TestCompose([LoadImage(), AddChannel(), Spacing(pixdim=(2, 2, 4)), RandAdjustContrast(prob=1.0)]),
+    TestCompose([LoadImage(image_only=True), AddChannel(), Spacing(pixdim=(2, 2, 4)), RandAdjustContrast(prob=1.0)]),
+    TestCompose([LoadImage(image_only=True), AddChannel(), Spacing(pixdim=(2, 2, 4)), RandAdjustContrast(prob=1.0)]),
     (0, 2),
     (1, 64, 64, 33),
 ]
 
-TEST_CASE_4 = [Compose([LoadImage(), AddChannel(), RandGaussianNoise(prob=1.0)]), (1, 128, 128, 128)]
+TEST_CASE_4 = [Compose([LoadImage(image_only=True), AddChannel(), RandGaussianNoise(prob=1.0)]), (1, 128, 128, 128)]
 
 
 class TestArrayDataset(unittest.TestCase):

tests/test_decollate.py

@@ -131,7 +131,7 @@ def test_decollation_dict(self, *transforms):
         t_compose = Compose([AddChanneld(KEYS), Compose(transforms), ToTensord(KEYS)])
         # If nibabel present, read from disk
         if has_nib:
-            t_compose = Compose([LoadImaged("image"), t_compose])
+            t_compose = Compose([LoadImaged("image", image_only=True), t_compose])
 
         dataset = CacheDataset(self.data_dict, t_compose, progress=False)
         self.check_decollate(dataset=dataset)
@@ -141,7 +141,7 @@ def test_decollation_tensor(self, *transforms):
         t_compose = Compose([AddChannel(), Compose(transforms), ToTensor()])
         # If nibabel present, read from disk
         if has_nib:
-            t_compose = Compose([LoadImage(), t_compose])
+            t_compose = Compose([LoadImage(image_only=True), t_compose])
 
         dataset = Dataset(self.data_list, t_compose)
         self.check_decollate(dataset=dataset)
@@ -151,7 +151,7 @@ def test_decollation_list(self, *transforms):
         t_compose = Compose([AddChannel(), Compose(transforms), ToTensor()])
         # If nibabel present, read from disk
         if has_nib:
-            t_compose = Compose([LoadImage(), t_compose])
+            t_compose = Compose([LoadImage(image_only=True), t_compose])
 
         dataset = Dataset(self.data_list, t_compose)
         self.check_decollate(dataset=dataset)

tests/test_ensure_channel_first.py

@@ -52,13 +52,13 @@ def test_load_nifti(self, input_param, filenames, original_channel_dim):
                 filenames[i] = os.path.join(tempdir, name)
                 nib.save(nib.Nifti1Image(test_image, np.eye(4)), filenames[i])
 
-            result = LoadImage(**input_param)(filenames)
+            result = LoadImage(image_only=True, **input_param)(filenames)
             result = EnsureChannelFirst()(result)
             self.assertEqual(result.shape[0], len(filenames))
 
     @parameterized.expand([TEST_CASE_7])
     def test_itk_dicom_series_reader(self, input_param, filenames, _):
-        result = LoadImage(**input_param)(filenames)
+        result = LoadImage(image_only=True, **input_param)(filenames)
         result = EnsureChannelFirst()(result)
         self.assertEqual(result.shape[0], 1)
 
@@ -68,7 +68,7 @@ def test_load_png(self):
         with tempfile.TemporaryDirectory() as tempdir:
             filename = os.path.join(tempdir, "test_image.png")
             Image.fromarray(test_image.astype("uint8")).save(filename)
-            result = LoadImage()(filename)
+            result = LoadImage(image_only=True)(filename)
             result = EnsureChannelFirst()(result)
             self.assertEqual(result.shape[0], 3)
 

tests/test_ensure_type.py

@@ -14,6 +14,7 @@
 import numpy as np
 import torch
 
+from monai.data import MetaTensor
 from monai.transforms import EnsureType
 from tests.utils import assert_allclose
 
@@ -59,9 +60,9 @@ def test_string(self):
 
     def test_list_tuple(self):
         for dtype in ("tensor", "numpy"):
-            result = EnsureType(data_type=dtype, wrap_sequence=False)([[1, 2], [3, 4]])
+            result = EnsureType(data_type=dtype, wrap_sequence=False, track_meta=True)([[1, 2], [3, 4]])
             self.assertTrue(isinstance(result, list))
-            self.assertTrue(isinstance(result[0][1], torch.Tensor if dtype == "tensor" else np.ndarray))
+            self.assertTrue(isinstance(result[0][1], MetaTensor if dtype == "tensor" else np.ndarray))
             torch.testing.assert_allclose(result[1][0], torch.as_tensor(3))
             # tuple of numpy arrays
             result = EnsureType(data_type=dtype, wrap_sequence=False)((np.array([1, 2]), np.array([3, 4])))
@@ -77,7 +78,7 @@ def test_dict(self):
             "extra": None,
         }
         for dtype in ("tensor", "numpy"):
-            result = EnsureType(data_type=dtype)(test_data)
+            result = EnsureType(data_type=dtype, track_meta=False)(test_data)
             self.assertTrue(isinstance(result, dict))
             self.assertTrue(isinstance(result["img"], torch.Tensor if dtype == "tensor" else np.ndarray))
             torch.testing.assert_allclose(result["img"], torch.as_tensor([1.0, 2.0]))