DICOM redactor improvement: Adding exceptions for when DICOM file doe…

…s not have pixel data (#1104)

* Adding exceptions for when DICOM file does not have pixel data

* Updating unit tests to accomodate new exception

* Fixing linting errors

* Adding in test image

* Fixing f-string

presidio-image-redactor/presidio_image_redactor/dicom_image_pii_verify_engine.py

@@ -66,6 +66,11 @@ def verify_dicom_instance(
         """
         instance_copy = deepcopy(instance)
 
+        try:
+            instance_copy.PixelData
+        except AttributeError:
+            raise AttributeError("Provided DICOM instance lacks pixel data.")
+
         # Load image for processing
         with tempfile.TemporaryDirectory() as tmpdirname:
             # Convert DICOM to PNG and add padding for OCR (during analysis)

presidio-image-redactor/presidio_image_redactor/dicom_image_redactor_engine.py

@@ -50,8 +50,13 @@ def redact(
         :return: DICOM instance with redacted pixel data.
         """
         # Check input
-        if type(image) != pydicom.dataset.FileDataset:
+        if type(image) not in [pydicom.dataset.FileDataset, pydicom.dataset.Dataset]:
             raise TypeError("The provided image must be a loaded DICOM instance.")
+        try:
+            image.PixelData
+        except AttributeError:
+            raise AttributeError("Provided DICOM instance lacks pixel data.")
+
         instance = deepcopy(image)
 
         # Load image for processing
@@ -771,6 +776,11 @@ def _redact_single_dicom_image(
         # Load instance
         instance = pydicom.dcmread(dst_path)
 
+        try:
+            instance.PixelData
+        except AttributeError:
+            raise AttributeError("Provided DICOM file lacks pixel data.")
+
         # Load image for processing
         with tempfile.TemporaryDirectory() as tmpdirname:
             # Convert DICOM to PNG and add padding for OCR (during analysis)

presidio-image-redactor/tests/test_dicom_image_pii_verify_engine.py

@@ -1,5 +1,6 @@
 """Unit tests for dicom_image_pii_verify_engine
 """
+from copy import deepcopy
 import pydicom
 
 from presidio_image_redactor import (
@@ -121,6 +122,28 @@ def test_verify_dicom_instance_happy_path(
     assert mock_analyze.call_count == 1
     assert mock_verify.call_count == 1
 
+def test_verify_dicom_instance_exception(
+    mock_engine: DicomImagePiiVerifyEngine,
+    get_mock_dicom_instance: pydicom.dataset.FileDataset,
+):
+    """Test exceptions for DicomImagePiiVerifyEngine.verify_dicom_instance
+    Args:
+        mock_engine (DicomImagePiiVerifyEngine): Instantiated engine.
+        get_mock_dicom_instance (pydicom.dataset.FileDataset): Loaded DICOM.
+    """
+    with pytest.raises(Exception) as exc_info:
+        # Arrange
+        padding_width = 25
+        test_instance = deepcopy(get_mock_dicom_instance)
+        del test_instance.PixelData
+        expected_error_type = AttributeError
+
+        # Act
+        _, _, _ = mock_engine.verify_dicom_instance(test_instance, padding_width)
+
+        # Assert
+        assert expected_error_type == exc_info.typename
+
 
 # ------------------------------------------------------
 # DicomImagePiiVerifyEngine.eval_dicom_instance()

presidio-image-redactor/tests/test_dicom_image_redactor_engine.py

@@ -41,6 +41,7 @@ def mock_engine():
             Path(TEST_DICOM_PARENT_DIR),
             [
                 Path(TEST_DICOM_PARENT_DIR, "0_ORIGINAL.dcm"),
+                Path(TEST_DICOM_PARENT_DIR, "0_ORIGINAL_no_pixels.dcm"),
                 Path(TEST_DICOM_PARENT_DIR, "RGB_ORIGINAL.dcm"),
                 Path(TEST_DICOM_DIR_2, "1_ORIGINAL.DCM"),
                 Path(TEST_DICOM_DIR_2, "2_ORIGINAL.dicom"),
@@ -537,7 +538,7 @@ def test_add_padding_exceptions(
     "src_path, expected_num_of_files",
     [
         (Path(TEST_DICOM_PARENT_DIR, "0_ORIGINAL.dcm"), 1),
-        (Path(TEST_DICOM_PARENT_DIR), 15),
+        (Path(TEST_DICOM_PARENT_DIR), 16),
         (Path(TEST_DICOM_DIR_1), 3),
         (Path(TEST_DICOM_DIR_2), 2),
         (Path(TEST_DICOM_DIR_3), 1),
@@ -1120,7 +1121,8 @@ def test_DicomImageRedactorEngine_redact_happy_path(
         (Path(TEST_DICOM_PARENT_DIR), "TypeError"),
         ("path_here", "TypeError"),
         (np.random.randint(255, size=(64, 64)), "TypeError"),
-        (Image.fromarray(np.random.randint(255, size=(400, 400),dtype=np.uint8)), "TypeError")
+        (Image.fromarray(np.random.randint(255, size=(400, 400),dtype=np.uint8)), "TypeError"),
+        (pydicom.dcmread(Path(TEST_DICOM_PARENT_DIR, "0_ORIGINAL_no_pixels.dcm")), "AttributeError")
     ],
 )
 def test_DicomImageRedactorEngine_redact_exceptions(
@@ -1255,6 +1257,7 @@ def save_as(self, dst_path: str):
     [
         (Path(TEST_DICOM_PARENT_DIR), "FileNotFoundError"),
         (Path("nonexistentfile.extension"), "FileNotFoundError"),
+        (Path(TEST_DICOM_PARENT_DIR, "0_ORIGINAL_no_pixels.dcm"), "AttributeError")
     ],
 )
 def test_DicomImageRedactorEngine_redact_single_dicom_image_exceptions(