Properly handle the exif orientation tag during ingest

isic/ingest/models/accession.py

@@ -27,6 +27,7 @@
 import numpy as np
 from osgeo import gdal
 import PIL.Image
+import PIL.ImageOps
 from s3_file_field import S3FileField
 
 from isic.core.models import CopyrightLicense, CreationSortedTimeStampedModel
@@ -511,6 +512,9 @@ def _generate_blob(self, img: PIL.Image.Image) -> AccessionBlob:
             # Any other errors are not expected, so re-raise them natively
             raise
 
+        # rotate the image bytes according to the orientation tag, stripping it in the process
+        PIL.ImageOps.exif_transpose(img, in_place=True)
+
         # Strip any alpha channel
         if self.is_color(img):
             img = img.convert("RGB")

isic/ingest/tests/test_accession.py

@@ -3,6 +3,8 @@
 from django.core.exceptions import ValidationError
 from django.core.files.uploadedfile import InMemoryUploadedFile
 from django.urls.base import reverse
+import PIL
+import PIL.ExifTags
 import pytest
 
 from isic.ingest.models.accession import Accession
@@ -35,6 +37,37 @@ def cc_by_accession_qs(accession_factory):
     return Accession.objects.filter(id=accession.id)
 
 
+@pytest.mark.django_db(transaction=True)
+def test_accession_orients_images(user, cohort):
+    name = "image_with_exif_including_orientation.jpg"
+    path = pathlib.Path(data_dir / name)
+
+    with path.open("rb") as stream:
+        original_blob = InMemoryUploadedFile(stream, None, name, None, path.stat().st_size, None)
+
+        original_image = PIL.Image.open(original_blob)
+
+        assert original_image._exif.get(PIL.ExifTags.Base.Make.value) == "Canon"
+        assert original_image._exif.get(PIL.ExifTags.Base.Orientation) == 6  # 90 degrees clockwise
+
+        accession = accession_create(
+            creator=user,
+            cohort=cohort,
+            original_blob=original_blob,
+            original_blob_name=name,
+            original_blob_size=path.stat().st_size,
+        )
+        accession.refresh_from_db()
+
+        processed_image = PIL.Image.open(accession.blob)
+
+        # assert that all exif data is stripped but the orientation is applied
+        assert processed_image._exif is None
+
+        assert original_image.height == processed_image.width
+        assert original_image.width == processed_image.height
+
+
 @pytest.mark.django_db(transaction=True)
 @pytest.mark.parametrize(
     ("blob_path", "blob_name", "mock_as_cog"),