[proto] Fixes Transform._transformed_types and torch.Tensor (#6487)

* Fixes unexpected behaviour with Transform._transformed_types and torch.Tensor

* Make code consistent to has_any, has_all implementation

* Fixed failing flake8 check

test/test_prototype_transforms.py

@@ -225,9 +225,18 @@ class TestSmoke:
             )
         ]
     )
-    def test_convertolor_space(self, transform, input):
+    def test_convert_color_space(self, transform, input):
         transform(input)
 
+    def test_convert_color_space_unsupported_types(self):
+        transform = transforms.ConvertColorSpace(
+            color_space=features.ColorSpace.RGB, old_color_space=features.ColorSpace.GRAY
+        )
+
+        for inpt in [make_bounding_box(format="XYXY"), make_segmentation_mask()]:
+            output = transform(inpt)
+            assert output is inpt
+
 
 @pytest.mark.parametrize("p", [0.0, 1.0])
 class TestRandomHorizontalFlip:

torchvision/prototype/transforms/_deprecated.py

@@ -3,7 +3,6 @@ from typing import Any, Dict, Optional
 
 import numpy as np
 import PIL.Image
-import torch
 import torchvision.prototype.transforms.functional as F
 from torchvision.prototype import features
 from torchvision.prototype.features import ColorSpace
@@ -18,7 +17,7 @@ from ._utils import is_simple_tensor
 class ToTensor(Transform):
 
     # Updated transformed types for ToTensor
-    _transformed_types = (torch.Tensor, features._Feature, PIL.Image.Image, np.ndarray)
+    _transformed_types = (is_simple_tensor, features._Feature, PIL.Image.Image, np.ndarray)
 
     def __init__(self) -> None:
         warnings.warn(
@@ -52,7 +51,7 @@ class PILToTensor(Transform):
 class ToPILImage(Transform):
 
     # Updated transformed types for ToPILImage
-    _transformed_types = (torch.Tensor, features._Feature, PIL.Image.Image, np.ndarray)
+    _transformed_types = (is_simple_tensor, features._Feature, PIL.Image.Image, np.ndarray)
 
     def __init__(self, mode: Optional[str] = None) -> None:
         warnings.warn(

torchvision/prototype/transforms/_meta.py

@@ -42,7 +42,7 @@ class ConvertImageDtype(Transform):
 
 class ConvertColorSpace(Transform):
     # F.convert_color_space does NOT handle `_Feature`'s in general
-    _transformed_types = (torch.Tensor, features.Image, PIL.Image.Image)
+    _transformed_types = (is_simple_tensor, features.Image, PIL.Image.Image)
 
     def __init__(
         self,

torchvision/prototype/transforms/_transform.py

 import enum
-from typing import Any, Dict, Tuple, Type
+from typing import Any, Callable, Dict, Tuple, Type, Union
 
 import PIL.Image
 import torch
 from torch import nn
 from torch.utils._pytree import tree_flatten, tree_unflatten
 from torchvision.prototype.features import _Feature
+from torchvision.prototype.transforms._utils import _isinstance, is_simple_tensor
 from torchvision.utils import _log_api_usage_once
 
 
 class Transform(nn.Module):
 
     # Class attribute defining transformed types. Other types are passed-through without any transformation
-    _transformed_types: Tuple[Type, ...] = (torch.Tensor, _Feature, PIL.Image.Image)
+    _transformed_types: Tuple[Union[Type, Callable[[Any], bool]], ...] = (is_simple_tensor, _Feature, PIL.Image.Image)
 
     def __init__(self) -> None:
         super().__init__()
@@ -31,7 +32,8 @@ class Transform(nn.Module):
 
         flat_inputs, spec = tree_flatten(sample)
         flat_outputs = [
-            self._transform(inpt, params) if isinstance(inpt, self._transformed_types) else inpt for inpt in flat_inputs
+            self._transform(inpt, params) if _isinstance(inpt, self._transformed_types) else inpt
+            for inpt in flat_inputs
         ]
         return tree_unflatten(flat_outputs, spec)
 

torchvision/prototype/transforms/_type_conversion.py

@@ -3,7 +3,6 @@ from typing import Any, Dict, Optional
 import numpy as np
 import PIL.Image
 
-import torch
 from torch.nn.functional import one_hot
 from torchvision.prototype import features
 from torchvision.prototype.transforms import functional as F, Transform
@@ -44,7 +43,7 @@ class LabelToOneHot(Transform):
 class ToImageTensor(Transform):
 
     # Updated transformed types for ToImageTensor
-    _transformed_types = (torch.Tensor, features._Feature, PIL.Image.Image, np.ndarray)
+    _transformed_types = (is_simple_tensor, features._Feature, PIL.Image.Image, np.ndarray)
 
     def __init__(self, *, copy: bool = False) -> None:
         super().__init__()
@@ -61,7 +60,7 @@ class ToImageTensor(Transform):
 class ToImagePIL(Transform):
 
     # Updated transformed types for ToImagePIL
-    _transformed_types = (torch.Tensor, features._Feature, PIL.Image.Image, np.ndarray)
+    _transformed_types = (is_simple_tensor, features._Feature, PIL.Image.Image, np.ndarray)
 
     def __init__(self, *, mode: Optional[str] = None) -> None:
         super().__init__()

torchvision/prototype/transforms/_utils.py

@@ -45,12 +45,18 @@ def query_chw(sample: Any) -> Tuple[int, int, int]:
     return chws.pop()
 
 
+def _isinstance(obj: Any, types_or_checks: Tuple[Union[Type, Callable[[Any], bool]], ...]) -> bool:
+    for type_or_check in types_or_checks:
+        if isinstance(obj, type_or_check) if isinstance(type_or_check, type) else type_or_check(obj):
+            return True
+    return False
+
+
 def has_any(sample: Any, *types_or_checks: Union[Type, Callable[[Any], bool]]) -> bool:
     flat_sample, _ = tree_flatten(sample)
-    for type_or_check in types_or_checks:
-        for obj in flat_sample:
-            if isinstance(obj, type_or_check) if isinstance(type_or_check, type) else type_or_check(obj):
-                return True
+    for obj in flat_sample:
+        if _isinstance(obj, types_or_checks):
+            return True
     return False