diff options
Diffstat (limited to 'synapse/rest/media/v1/thumbnailer.py')
| -rw-r--r-- | synapse/rest/media/v1/thumbnailer.py | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/synapse/rest/media/v1/thumbnailer.py b/synapse/rest/media/v1/thumbnailer.py index df54a406..46701a8b 100644 --- a/synapse/rest/media/v1/thumbnailer.py +++ b/synapse/rest/media/v1/thumbnailer.py @@ -61,9 +61,19 @@ class Thumbnailer: self.transpose_method = None try: # We don't use ImageOps.exif_transpose since it crashes with big EXIF - image_exif = self.image._getexif() + # + # Ignore safety: Pillow seems to acknowledge that this method is + # "private, experimental, but generally widely used". Pillow 6 + # includes a public getexif() method (no underscore) that we might + # consider using instead when we can bump that dependency. + # + # At the time of writing, Debian buster (currently oldstable) + # provides version 5.4.1. It's expected to EOL in mid-2022, see + # https://wiki.debian.org/DebianReleases#Production_Releases + image_exif = self.image._getexif() # type: ignore if image_exif is not None: image_orientation = image_exif.get(EXIF_ORIENTATION_TAG) + assert isinstance(image_orientation, int) self.transpose_method = EXIF_TRANSPOSE_MAPPINGS.get(image_orientation) except Exception as e: # A lot of parsing errors can happen when parsing EXIF @@ -76,7 +86,10 @@ class Thumbnailer: A tuple containing the new image size in pixels as (width, height). """ if self.transpose_method is not None: - self.image = self.image.transpose(self.transpose_method) + # Safety: `transpose` takes an int rather than e.g. an IntEnum. + # self.transpose_method is set above to be a value in + # EXIF_TRANSPOSE_MAPPINGS, and that only contains correct values. + self.image = self.image.transpose(self.transpose_method) # type: ignore[arg-type] self.width, self.height = self.image.size self.transpose_method = None # We don't need EXIF any more @@ -101,7 +114,7 @@ class Thumbnailer: else: return (max_height * self.width) // self.height, max_height - def _resize(self, width: int, height: int) -> Image: + def _resize(self, width: int, height: int) -> Image.Image: # 1-bit or 8-bit color palette images need converting to RGB # otherwise they will be scaled using nearest neighbour which # looks awful. @@ -151,7 +164,7 @@ class Thumbnailer: cropped = scaled_image.crop((crop_left, 0, crop_right, height)) return self._encode_image(cropped, output_type) - def _encode_image(self, output_image: Image, output_type: str) -> BytesIO: + def _encode_image(self, output_image: Image.Image, output_type: str) -> BytesIO: output_bytes_io = BytesIO() fmt = self.FORMATS[output_type] if fmt == "JPEG": |