Merge pull request #557 from bioimage-io/optional_inputs

Optional input tensors

README.md

@@ -228,6 +228,11 @@ Made with [contrib.rocks](https://contrib.rocks).
 
 ### Resource Description Format Versions
 
+#### model 0.5.1 (planned)
+
+* Non-breaking changes
+  * added optional `inputs.i.optional` field to indicate that a tensor may be `None`
+
 #### generic 0.3.0 / application 0.3.0 / collection 0.3.0 / dataset 0.3.0 / notebook 0.3.0
 
 * Breaking canges that are fully auto-convertible

bioimageio/spec/model/v0_5.py

@@ -60,7 +60,7 @@
 from .._internal.io import BioimageioYamlContent as BioimageioYamlContent
 from .._internal.io import FileDescr as FileDescr
 from .._internal.io import Sha256 as Sha256
-from .._internal.io import WithSuffix, download
+from .._internal.io import WithSuffix, YamlValue, download
 from .._internal.io_basics import AbsoluteFilePath as AbsoluteFilePath
 from .._internal.io_utils import load_array
 from .._internal.types import Datetime as Datetime
@@ -246,6 +246,9 @@ def get_size(self, n: ParameterizedSize.N) -> int:
         return self.min + self.step * n
 
 
+ARBITRARY_SIZE = ParameterizedSize(min=1, step=1)
+
+
 class SizeReference(Node):
     """A tensor axis size (extent in pixels/frames) defined in relation to a reference axis.
 
@@ -1028,6 +1031,9 @@ class InputTensorDescr(TensorDescrBase[InputAxis]):
     """Input tensor id.
     No duplicates are allowed across all inputs and outputs."""
 
+    optional: bool = False
+    """indicates that this tensor may be `None`"""
+
     preprocessing: List[PreprocessingDescr] = Field(default_factory=list)
     """Description of how this input should be preprocessed."""
 
@@ -1464,7 +1470,7 @@ class _ArchitectureCallableDescr(Node):
     callable: Annotated[Identifier, Field(examples=["MyNetworkClass", "get_my_model"])]
     """Identifier of the callable that returns a torch.nn.Module instance."""
 
-    kwargs: Dict[str, Any] = Field(default_factory=dict)
+    kwargs: Dict[str, YamlValue] = Field(default_factory=dict)
     """key word arguments for the `callable`"""