added Normalization transformation to per_sample transforms

CHANGELOG.md

@@ -22,6 +22,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 - Added support for loading `ObjectDetectionData` with `from_numpy`, `from_images`, and `from_tensors` ([#1372](https://github.com/PyTorchLightning/lightning-flash/pull/1372))
 
+- Added support for normalization of images in `SemanticSegmentationData` ([#1399](https://github.com/PyTorchLightning/lightning-flash/pull/1399))
+
 ### Changed
 
 - Changed the `ImageEmbedder` dependency on VISSL to optional ([#1276](https://github.com/PyTorchLightning/lightning-flash/pull/1276))

flash/image/segmentation/input_transform.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 from dataclasses import dataclass
-from typing import Any, Callable, Dict, Tuple
+from typing import Any, Callable, Dict, Tuple, Union
 
 from flash.core.data.io.input import DataKeys
 from flash.core.data.io.input_transform import InputTransform
@@ -44,23 +44,43 @@ def remove_extra_dimensions(batch: Dict[str, Any]):
 class SemanticSegmentationInputTransform(InputTransform):
 
     image_size: Tuple[int, int] = (128, 128)
+    mean: Union[float, Tuple[float, float, float]] = (0.485, 0.456, 0.406)
+    std: Union[float, Tuple[float, float, float]] = (0.229, 0.224, 0.225)
 
     def train_per_sample_transform(self) -> Callable:
-        return ApplyToKeys(
-            [DataKeys.INPUT, DataKeys.TARGET],
-            KorniaParallelTransforms(
-                K.geometry.Resize(self.image_size, interpolation="nearest"), K.augmentation.RandomHorizontalFlip(p=0.5)
-            ),
+        return T.Compose(
+            [
+                ApplyToKeys(
+                    [DataKeys.INPUT, DataKeys.TARGET],
+                    KorniaParallelTransforms(
+                        K.geometry.Resize(self.image_size, interpolation="nearest"),
+                        K.augmentation.RandomHorizontalFlip(p=0.5),
+                    ),
+                ),
+                ApplyToKeys([DataKeys.INPUT], K.augmentation.Normalize(mean=self.mean, std=self.std)),
+            ]
         )
 
     def per_sample_transform(self) -> Callable:
-        return ApplyToKeys(
-            [DataKeys.INPUT, DataKeys.TARGET],
-            KorniaParallelTransforms(K.geometry.Resize(self.image_size, interpolation="nearest")),
+        return T.Compose(
+            [
+                ApplyToKeys(
+                    [DataKeys.INPUT, DataKeys.TARGET],
+                    KorniaParallelTransforms(K.geometry.Resize(self.image_size, interpolation="nearest")),
+                ),
+                ApplyToKeys([DataKeys.INPUT], K.augmentation.Normalize(mean=self.mean, std=self.std)),
+            ]
         )
 
     def predict_per_sample_transform(self) -> Callable:
-        return ApplyToKeys(DataKeys.INPUT, K.geometry.Resize(self.image_size, interpolation="nearest"))
+        return ApplyToKeys(
+            DataKeys.INPUT,
+            K.geometry.Resize(
+                self.image_size,
+                interpolation="nearest",
+            ),
+            K.augmentation.Normalize(mean=self.mean, std=self.std),
+        )
 
     def collate(self) -> Callable:
         return kornia_collate