Ensure TIFF has transposed on load before checking orientation

Tests/test_file_libtiff.py

@@ -8,7 +8,7 @@
 
 import pytest
 
-from PIL import Image, ImageFilter, TiffImagePlugin, TiffTags, features
+from PIL import Image, ImageFilter, ImageOps, TiffImagePlugin, TiffTags, features
 from PIL.TiffImagePlugin import SAMPLEFORMAT, STRIPOFFSETS, SUBIFD
 
 from .helper import (
@@ -1039,6 +1039,14 @@ def test_orientation(self):
 
                     assert_image_similar(base_im, im, 0.7)
 
+    def test_exif_transpose(self):
+        with Image.open("Tests/images/g4_orientation_1.tif") as base_im:
+            for i in range(2, 9):
+                with Image.open("Tests/images/g4_orientation_" + str(i) + ".tif") as im:
+                    im = ImageOps.exif_transpose(im)
+
+                    assert_image_similar(base_im, im, 0.7)
+
     @pytest.mark.valgrind_known_error(reason="Backtrace in Python Core")
     def test_sampleformat_not_corrupted(self):
         # Assert that a TIFF image with SampleFormat=UINT tag is not corrupted

src/PIL/ImageOps.py

@@ -588,6 +588,7 @@ def exif_transpose(image, *, in_place=False):
         with the transposition applied. If there is no transposition, a copy of the
         image will be returned.
     """
+    image.load()
     image_exif = image.getexif()
     orientation = image_exif.get(ExifTags.Base.Orientation)
     method = {