MONAISegInferenceOperator Additional Arguments (#547)

* mode + padding_mode input args added

Signed-off-by: bluna301 <[email protected]>

* StrEnums from MONAI Core; kwargs filtering for sliding_window_inference forwarding

Signed-off-by: bluna301 <[email protected]>

* holoscan conversion check + explicit params added + setter cleanup

Signed-off-by: bluna301 <[email protected]>

* split kwargs into swi params & base init params

Signed-off-by: bluna301 <[email protected]>

* removed redundant continues

Signed-off-by: bluna301 <[email protected]>

---------

Signed-off-by: bluna301 <[email protected]>

Author: bluna301

monai/deploy/core/__init__.py

@@ -1,4 +1,4 @@
-# Copyright 2021 MONAI Consortium
+# Copyright 2021-2025 MONAI Consortium
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
@@ -30,7 +30,7 @@
 
 # Need to import explicit ones to quiet mypy complaints
 from holoscan.core import *
-from holoscan.core import Application, Condition, ConditionType, Fragment, Operator, OperatorSpec
+from holoscan.core import Application, Condition, ConditionType, Fragment, Operator, OperatorSpec, Resource
 
 from .app_context import AppContext, init_app_context
 from .arg_parser import parse_args

monai/deploy/operators/monai_seg_inference_operator.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2023 MONAI Consortium
+# Copyright 2021-2025 MONAI Consortium
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
@@ -9,6 +9,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import inspect
 import logging
 import os
 from pathlib import Path
@@ -40,7 +41,7 @@
 # Dynamic class is not handled so make it Any for now: https://github.com/python/mypy/issues/2477
 Compose: Any = Compose_
 
-from monai.deploy.core import AppContext, ConditionType, Fragment, Image, OperatorSpec
+from monai.deploy.core import AppContext, Condition, ConditionType, Fragment, Image, OperatorSpec, Resource
 
 from .inference_operator import InferenceOperator
 
@@ -56,14 +57,20 @@ class InfererType(StrEnum):
 
 # @md.env(pip_packages=["monai>=1.0.0", "torch>=1.10.2", "numpy>=1.21"])
 class MonaiSegInferenceOperator(InferenceOperator):
-    """This segmentation operator uses MONAI transforms and Sliding Window Inference.
+    """This segmentation operator uses MONAI transforms and performs Simple or Sliding Window Inference.
 
     This operator performs pre-transforms on a input image, inference
     using a given model, and post-transforms. The segmentation image is saved
     as a named Image object in memory.
 
     If specified in the post transforms, results may also be saved to disk.
 
+    This operator uses the MONAI inference utils functions for sliding window and simple inference,
+    and thus input parameters need to be as expected by these functions.
+
+    Any additional sliding window arguments not explicitly defined in this operator can be passed via
+    **kwargs for forwarding to 'sliding_window_inference'.
+
     Named Input:
         image: Image object of the input image.
 
@@ -74,6 +81,63 @@ class MonaiSegInferenceOperator(InferenceOperator):
     # For testing the app directly, the model should be at the following path.
     MODEL_LOCAL_PATH = Path(os.environ.get("HOLOSCAN_MODEL_PATH", Path.cwd() / "model/model.ts"))
 
+    @staticmethod
+    def filter_sw_kwargs(**kwargs) -> Tuple[Dict[str, Any], Dict[str, Any]]:
+        """
+        Filters the keyword arguments into a tuple of two dictionaries:
+
+        1. A dictionary of named parameters to pass to the sliding_window_inference function that:
+            - Are not explicitly defined in the __init__ of this class
+            - Are not explicitly used when calling sliding_window_inference
+
+        2. A dicionary of named parameters to pass to the base class __init__ of this class that:
+            - Are not used when calling sliding_window_inference
+            - Can be successfully converted from Python --> Holoscan's C++ layer
+
+        Args:
+            **kwargs: extra arguments passed into __init__ beyond the explicitly defined args.
+
+        Returns:
+            filtered_swi_params: A filtered dictionary of arguments to be passed to sliding_window_inference.
+            filtered_base_init_params: A filtered dictionary of arguments to be passed to the base class __init__.
+        """
+
+        logger = logging.getLogger(f"{__name__}.{MonaiSegInferenceOperator.__name__}")
+
+        init_params = inspect.signature(MonaiSegInferenceOperator).parameters
+        swi_params = inspect.signature(sliding_window_inference).parameters
+
+        # inputs + predictor explicitly used when calling sliding_window_inference
+        explicit_used = {"inputs", "predictor"}
+
+        # Holoscan convertible types (not exhaustive)
+        # This will be revisited when there is a better way to handle this.
+        allowed_types = (str, int, float, bool, bytes, list, tuple, torch.Tensor, Condition, Resource)
+
+        filtered_swi_params = {}
+        filtered_base_init_params = {}
+
+        for name, val in kwargs.items():
+            # Drop explicitly defined kwargs
+            if name in init_params or name in explicit_used:
+                logger.warning(f"{name!r} is already explicitly defined or used; dropping kwarg.")
+            # SWI params
+            elif name in swi_params:
+                filtered_swi_params[name] = val
+                logger.debug(f"{name!r} used in sliding_window_inference; keeping kwarg for inference call.")
+            # Drop kwargs that can't be converted by Holoscan
+            elif not isinstance(val, allowed_types):
+                logger.warning(
+                    f"{name!r} type of {type(val).__name__!r} is a non-convertible kwarg for Holoscan; dropping kwarg."
+                )
+            # Base __init__ params
+            else:
+                filtered_base_init_params[name] = val
+                logger.debug(
+                    f"{name!r} type of {type(val).__name__!r} can be converted by Holoscan; keeping kwarg for base init."
+                )
+        return filtered_swi_params, filtered_base_init_params
+
     def __init__(
         self,
         fragment: Fragment,
@@ -83,7 +147,7 @@ def __init__(
         post_transforms: Compose,
         app_context: AppContext,
         model_name: Optional[str] = "",
-        overlap: float = 0.25,
+        overlap: Union[Sequence[float], float] = 0.25,
         sw_batch_size: int = 4,
         inferer: Union[InfererType, str] = InfererType.SLIDING_WINDOW,
         model_path: Path = MODEL_LOCAL_PATH,
@@ -93,19 +157,19 @@ def __init__(
 
         Args:
             fragment (Fragment): An instance of the Application class which is derived from Fragment.
-            roi_size (Union[Sequence[int], int]): The window size to execute "SLIDING_WINDOW" evaluation.
-                                                  An optional input only to be passed for "SLIDING_WINDOW".
-                                                  If using a "SIMPLE" Inferer, this input is ignored.
+            roi_size (Sequence[int], int, optional): The window size to execute "SLIDING_WINDOW" evaluation.
+                             Applicable for "SLIDING_WINDOW" only.
             pre_transforms (Compose): MONAI Compose object used for pre-transforms.
             post_transforms (Compose): MONAI Compose object used for post-transforms.
             app_context (AppContext): Object holding the I/O and model paths, and potentially loaded models.
             model_name (str, optional): Name of the model. Default to "" for single model app.
-            overlap (float): The amount of overlap between scans along each spatial dimension. Defaults to 0.25.
+            overlap (Sequence[float], float): The amount of overlap between scans along each spatial dimension. Defaults to 0.25.
+                             Applicable for "SLIDING_WINDOW" only.
+            sw_batch_size (int): The batch size to run window slices. Defaults to 4.
                              Applicable for "SLIDING_WINDOW" only.
-            sw_batch_size(int): The batch size to run window slices. Defaults to 4.
-                                Applicable for "SLIDING_WINDOW" only.
-            inferer (InfererType): The type of inferer to use, "SIMPLE" or "SLIDING_WINDOW". Defaults to "SLIDING_WINDOW".
+            inferer (InfererType, str): The type of inferer to use, "SIMPLE" or "SLIDING_WINDOW". Defaults to "SLIDING_WINDOW".
             model_path (Path): Path to the model file. Defaults to model/models.ts of current working dir.
+            **kwargs: any other sliding window parameters to forward (e.g. `mode`, `cval`, etc.).
         """
 
         self._logger = logging.getLogger("{}.{}".format(__name__, type(self).__name__))
@@ -115,26 +179,30 @@ def __init__(
         self._pred_dataset_key = "pred"
         self._input_image = None  # Image will come in when compute is called.
         self._reader: Any = None
-        self._roi_size = ensure_tuple(roi_size)
-        self._pre_transform = pre_transforms
-        self._post_transforms = post_transforms
+        self.roi_size = ensure_tuple(roi_size)
+        self.pre_transforms = pre_transforms
+        self.post_transforms = post_transforms
         self._model_name = model_name.strip() if isinstance(model_name, str) else ""
-        self._overlap = overlap
-        self._sw_batch_size = sw_batch_size
-        self._inferer = inferer
+        self.overlap = overlap
+        self.sw_batch_size = sw_batch_size
+        self.inferer = inferer
+        self._filtered_swi_params, self._filtered_base_init_params = self.filter_sw_kwargs(
+            **kwargs
+        )  # Filter keyword args
 
         # Add this so that the local model path can be set from the calling app
         self.model_path = model_path
-        self.input_name_image = "image"
-        self.output_name_seg = "seg_image"
+        self._input_name_image = "image"
+        self._output_name_seg = "seg_image"
 
         # The execution context passed in on compute does not have the required model info, so need to
         # get and keep the model via the AppContext obj on construction.
         self.app_context = app_context
 
-        self.model = self._get_model(self.app_context, self.model_path, self._model_name)
+        self._model = self._get_model(self.app_context, self.model_path, self._model_name)
 
-        super().__init__(fragment, *args, **kwargs)
+        # Pass filtered base init params
+        super().__init__(fragment, *args, **self._filtered_base_init_params)
 
     def _get_model(self, app_context: AppContext, model_path: Path, model_name: str):
         """Load the model with the given name from context or model path
@@ -159,8 +227,8 @@ def _get_model(self, app_context: AppContext, model_path: Path, model_name: str)
         return model
 
     def setup(self, spec: OperatorSpec):
-        spec.input(self.input_name_image)
-        spec.output(self.output_name_seg).condition(ConditionType.NONE)  # Downstream receiver optional.
+        spec.input(self._input_name_image)
+        spec.output(self._output_name_seg).condition(ConditionType.NONE)  # Downstream receiver optional.
 
     @property
     def roi_size(self):
@@ -199,9 +267,13 @@ def overlap(self):
         return self._overlap
 
     @overlap.setter
-    def overlap(self, val: float):
-        if val < 0 or val > 1:
-            raise ValueError("Overlap must be between 0 and 1.")
+    def overlap(self, val: Union[Sequence[float], float]):
+        if not isinstance(val, (Sequence, int, float)) or isinstance(val, str):
+            raise TypeError(f"Overlap must be type Sequence[float] | float, got {type(val).__name__}.")
+        elif isinstance(val, Sequence) and not all(isinstance(x, (int, float)) and 0 <= x < 1 for x in val):
+            raise ValueError("Each overlap value must be >= 0 and < 1.")
+        elif isinstance(val, (int, float)) and not (0 <= float(val) < 1):
+            raise ValueError(f"Overlap must be >= 0 and < 1, got {val}.")
         self._overlap = val
 
     @property
@@ -221,10 +293,20 @@ def inferer(self) -> Union[InfererType, str]:
         return self._inferer
 
     @inferer.setter
-    def inferer(self, val: InfererType):
-        if not isinstance(val, InfererType):
-            raise ValueError(f"Value must be of the correct type {InfererType}.")
-        self._inferer = val
+    def inferer(self, val: Union[InfererType, str]):
+        if isinstance(val, InfererType):
+            self._inferer = val
+            return
+
+        if isinstance(val, str):
+            s = val.strip().lower()
+            valid = (InfererType.SIMPLE.value, InfererType.SLIDING_WINDOW.value)
+            if s in valid:
+                self._inferer = InfererType(s)
+                return
+            raise ValueError(f"inferer must be one of {valid}, got {val!r}.")
+
+        raise TypeError(f"inferer must be InfererType or str, got {type(val).__name__}.")
 
     def _convert_dicom_metadata_datatype(self, metadata: Dict):
         """Converts metadata in pydicom types to the corresponding native types.
@@ -279,10 +361,10 @@ def compute(self, op_input, op_output, context):
             else:
                 self._executing = True
         try:
-            input_image = op_input.receive(self.input_name_image)
+            input_image = op_input.receive(self._input_name_image)
             if not input_image:
                 raise ValueError("Input is None.")
-            op_output.emit(self.compute_impl(input_image, context), self.output_name_seg)
+            op_output.emit(self.compute_impl(input_image, context), self._output_name_seg)
         finally:
             # Reset state on completing this method execution.
             with self._lock:
@@ -297,12 +379,12 @@ def compute_impl(self, input_image, context):
         # Need to give a name to the image as in-mem Image obj has no name.
         img_name = str(input_img_metadata.get("SeriesInstanceUID", "Img_in_context"))
 
-        pre_transforms: Compose = self._pre_transform
-        post_transforms: Compose = self._post_transforms
+        pre_transforms: Compose = self.pre_transforms
+        post_transforms: Compose = self.post_transforms
         self._reader = InMemImageReader(input_image)
 
-        pre_transforms = self._pre_transform if self._pre_transform else self.pre_process(self._reader)
-        post_transforms = self._post_transforms if self._post_transforms else self.post_process(pre_transforms)
+        pre_transforms = self.pre_transforms if self.pre_transforms else self.pre_process(self._reader)
+        post_transforms = self.post_transforms if self.post_transforms else self.post_process(pre_transforms)
 
         device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
         dataset = Dataset(data=[{self._input_dataset_key: img_name}], transform=pre_transforms)
@@ -314,20 +396,21 @@ def compute_impl(self, input_image, context):
             for d in dataloader:
                 images = d[self._input_dataset_key].to(device)
                 self._logger.info(f"Input of {type(images)} shape: {images.shape}")
-                if self._inferer == InfererType.SLIDING_WINDOW:
+                if self.inferer == InfererType.SLIDING_WINDOW:
                     d[self._pred_dataset_key] = sliding_window_inference(
                         inputs=images,
-                        roi_size=self._roi_size,
-                        sw_batch_size=self.sw_batch_size,
+                        roi_size=self.roi_size,
                         overlap=self.overlap,
-                        predictor=self.model,
+                        sw_batch_size=self.sw_batch_size,
+                        predictor=self._model,
+                        **self._filtered_swi_params,  # Additional sliding window arguments
                     )
-                elif self._inferer == InfererType.SIMPLE:
+                elif self.inferer == InfererType.SIMPLE:
                     # Instantiates the SimpleInferer and directly uses its __call__ function
-                    d[self._pred_dataset_key] = simple_inference()(inputs=images, network=self.model)
+                    d[self._pred_dataset_key] = simple_inference()(inputs=images, network=self._model)
                 else:
                     raise ValueError(
-                        f"Unknown inferer: {self._inferer!r}. Available options are "
+                        f"Unknown inferer: {self.inferer!r}. Available options are "
                         f"{InfererType.SLIDING_WINDOW!r} and {InfererType.SIMPLE!r}."
                     )