fixes tutorial #82

monai/data/image_reader.py

@@ -28,12 +28,14 @@
     from itk import Image  # type: ignore
     from nibabel.nifti1 import Nifti1Image
     from PIL import Image as PILImage
+
+    has_itk = has_nib = has_pil = True
 else:
-    itk, _ = optional_import("itk", allow_namespace_pkg=True)
+    itk, has_itk = optional_import("itk", allow_namespace_pkg=True)
     Image, _ = optional_import("itk", allow_namespace_pkg=True, name="Image")
-    nib, _ = optional_import("nibabel")
+    nib, has_nib = optional_import("nibabel")
     Nifti1Image, _ = optional_import("nibabel.nifti1", name="Nifti1Image")
-    PILImage, _ = optional_import("PIL.Image")
+    PILImage, has_pil = optional_import("PIL.Image")
 
 
 class ImageReader(ABC):
@@ -121,7 +123,7 @@ class ITKReader(ImageReader):
     def __init__(self, **kwargs):
         super().__init__()
         self.kwargs = kwargs
-        if int(itk.Version.GetITKMajorVersion()) == 5 and int(itk.Version.GetITKMinorVersion()) < 2:
+        if has_itk and int(itk.Version.GetITKMajorVersion()) == 5 and int(itk.Version.GetITKMinorVersion()) < 2:
             # warning the ITK LazyLoading mechanism was not threadsafe until version 5.2.0,
             # requesting access to the itk.imread function triggers the lazy loading of the relevant itk modules
             # before the parallel use of the function.
@@ -136,7 +138,7 @@ def verify_suffix(self, filename: Union[Sequence[str], str]) -> bool:
                 if a list of files, verify all the suffixes.
 
         """
-        return True
+        return has_itk
 
     def read(self, data: Union[Sequence[str], str], **kwargs):
         """
@@ -307,7 +309,7 @@ def verify_suffix(self, filename: Union[Sequence[str], str]) -> bool:
 
         """
         suffixes: Sequence[str] = ["nii", "nii.gz"]
-        return is_supported_format(filename, suffixes)
+        return has_nib and is_supported_format(filename, suffixes)
 
     def read(self, data: Union[Sequence[str], str], **kwargs):
         """
@@ -522,7 +524,7 @@ def verify_suffix(self, filename: Union[Sequence[str], str]) -> bool:
                 if a list of files, verify all the suffixes.
         """
         suffixes: Sequence[str] = ["png", "jpg", "bmp"]
-        return is_supported_format(filename, suffixes)
+        return has_pil and is_supported_format(filename, suffixes)
 
     def read(self, data: Union[Sequence[str], str, np.ndarray], **kwargs):
         """

monai/transforms/io/array.py

@@ -70,13 +70,14 @@ def __init__(
         if reader is not None:
             if isinstance(reader, str):
                 supported_readers = {
-                    "NibabelReader": NibabelReader,
-                    "PILReader": PILReader,
-                    "ITKReader": ITKReader,
-                    "NumpyReader": NumpyReader,
+                    "nibabelreader": NibabelReader,
+                    "pilreader": PILReader,
+                    "itkreader": ITKReader,
+                    "numpyreader": NumpyReader,
                 }
+                reader = reader.lower()
                 if reader not in supported_readers:
-                    raise ValueError(f"unsupported reader type: {reader}.")
+                    raise ValueError(f"unsupported reader type: {reader}, available options: {supported_readers}.")
                 self.register(supported_readers[reader](*args, **kwargs))
             else:
                 self.register(reader)

tests/test_init_reader.py

@@ -0,0 +1,48 @@
+# Copyright 2020 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
+#     http://www.apache.org/licenses/LICENSE-2.0
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+
+from monai.data import ITKReader, NibabelReader, NumpyReader, PILReader
+from monai.transforms import LoadImage, LoadImaged
+
+
+class TestInitLoadImage(unittest.TestCase):
+    def test_load_image(self):
+        instance1 = LoadImage(image_only=False, dtype=None)
+        instance2 = LoadImage(image_only=True, dtype=None)
+        self.assertIsInstance(instance1, LoadImage)
+        self.assertIsInstance(instance2, LoadImage)
+
+        for r in ["NibabelReader", "PILReader", "ITKReader", "NumpyReader", None]:
+            inst = LoadImaged("image", reader=r)
+            self.assertIsInstance(inst, LoadImaged)
+
+    def test_readers(self):
+        inst = ITKReader()
+        self.assertIsInstance(inst, ITKReader)
+
+        inst = NibabelReader()
+        self.assertIsInstance(inst, NibabelReader)
+        inst = NibabelReader(as_closest_canonical=True)
+        self.assertIsInstance(inst, NibabelReader)
+
+        inst = NumpyReader()
+        self.assertIsInstance(inst, NumpyReader)
+        inst = NumpyReader(npz_keys="test")
+        self.assertIsInstance(inst, NumpyReader)
+
+        inst = PILReader()
+        self.assertIsInstance(inst, PILReader)
+
+
+if __name__ == "__main__":
+    unittest.main()