Resolves #51 (#56)

pillow_heif/heif.py

@@ -666,17 +666,18 @@ def save(self, fp, **kwargs) -> None:
             (default = ``True``)
 
             ``append_images`` - do the same as in Pillow.
-            Accept ``HeifFile``, ``HeifImage`` and ``PIL.Image``
+            Accepts ``HeifFile``, ``HeifImage`` and ``PIL.Image``
 
             .. note:: Appended images always will have ``info["primary"]=False``
 
             ``quality`` - see :py:attr:`~pillow_heif._options.PyLibHeifOptions.quality`
 
             ``enc_params`` - dictionary with key:value to pass to :ref:`x265 <hevc-encoder>` encoder.
 
-            ``exif`` - override primary image's EXIF with specified. Accept ``None`` or ``bytes``.
+            ``exif`` - override primary image's EXIF with specified.
+            Accepts ``None``, ``bytes`` or ``PIL.Image.Exif`` class.
 
-            ``xmp`` - override primary image's XMP with specified. Accept ``None`` or ``bytes``.
+            ``xmp`` - override primary image's XMP with specified. Accepts ``None`` or ``bytes``.
 
             ``primary_index`` - ignore ``info["primary"]`` and set `PrimaryImage` by index.
 
@@ -772,6 +773,8 @@ def _save(ctx: LibHeifCtxWrite, img_list: List[HeifImage], primary_index: int, *
                     lib.heif_context_set_primary_image(ctx.ctx, new_img_handle)
                 if kwargs.get("exif", -1) != -1:
                     exif = kwargs["exif"]
+                    if isinstance(exif, Image.Exif):
+                        exif = exif.tobytes()
                 if kwargs.get("xmp", -1) != -1:
                     xmp = kwargs["xmp"]
             set_exif(ctx, new_img_handle, exif)

tests/metadata_exif_test.py

@@ -175,3 +175,18 @@ def test_corrupted_exif():
     with pytest.raises(SyntaxError):
         im.getexif()
     assert im.info["exif"] == exif_data
+
+
+@pytest.mark.skipif(not helpers.hevc_enc(), reason="Requires HEVC encoder.")
+def test_exif_as_class():
+    exif = Image.Exif()
+    exif[258] = 8
+    exif[40963] = 455
+    exif[305] = "exif test"
+    out_im = BytesIO()
+    helpers.gradient_rgb().save(out_im, format="HEIF", exif=exif)
+    im = Image.open(out_im)
+    exif = im.getexif()
+    assert exif[258] == 8
+    assert exif[40963] == 455
+    assert exif[305] == "exif test"