Transpose images with EXIF Orientation tag

src/datasets/features/image.py

@@ -154,6 +154,7 @@ def decode_example(self, value: dict, token_per_repo_id=None) -> "PIL.Image.Imag
 
         if config.PIL_AVAILABLE:
             import PIL.Image
+            import PIL.ImageOps
         else:
             raise ImportError("To support decoding images, please install 'Pillow'.")
 
@@ -186,6 +187,8 @@ def decode_example(self, value: dict, token_per_repo_id=None) -> "PIL.Image.Imag
         else:
             image = PIL.Image.open(BytesIO(bytes_))
         image.load()  # to avoid "Too many open files" errors
+        if image.getexif().get(PIL.Image.ExifTags.Base.Orientation) is not None:
+            image = PIL.ImageOps.exif_transpose(image)
         if self.mode and self.mode != image.mode:
             image = image.convert(self.mode)
         return image

tests/features/test_image.py

@@ -1,6 +1,7 @@
 import os
 import tarfile
 import warnings
+from io import BytesIO
 
 import numpy as np
 import pandas as pd
@@ -90,6 +91,24 @@ def test_image_decode_example(shared_datadir):
         Image(decode=False).decode_example(image_path)
 
 
+@require_pil
+def test_image_decode_example_with_exif_orientation_tag(shared_datadir):
+    import PIL.Image
+
+    image_path = str(shared_datadir / "test_image_rgb.jpg")
+    buffer = BytesIO()
+    exif = PIL.Image.Exif()
+    exif[PIL.Image.ExifTags.Base.Orientation] = 8  # rotate the image for 90°
+    PIL.Image.open(image_path).save(buffer, format="JPEG", exif=exif.tobytes())
+    image = Image()
+
+    decoded_example = image.decode_example({"path": None, "bytes": buffer.getvalue()})
+
+    assert isinstance(decoded_example, PIL.Image.Image)
+    assert decoded_example.size == (480, 640)  # rotated
+    assert decoded_example.mode == "RGB"
+
+
 @require_pil
 def test_image_change_mode(shared_datadir):
     import PIL.Image