fix: Convert EXIF orientation to avif irot and imir

src/pillow_avif/AvifImagePlugin.py

@@ -3,7 +3,7 @@
 from io import BytesIO
 import sys
 
-from PIL import Image, ImageFile
+from PIL import ExifTags, Image, ImageFile
 
 try:
     from pillow_avif import _avif
@@ -56,6 +56,9 @@ class AvifImageFile(ImageFile.ImageFile):
     __loaded = -1
     __frame = 0
 
+    def load_seek(self, pos):
+        pass
+
     def _open(self):
         self._decoder = _avif.AvifDecoder(
             self.fp.read(), DECODE_CODEC_CHOICE, CHROMA_UPSAMPLING
@@ -146,6 +149,20 @@ def _save(im, fp, filename, save_all=False):
     exif = info.get("exif", im.info.get("exif"))
     if isinstance(exif, Image.Exif):
         exif = exif.tobytes()
+
+    exif_orientation = 0
+    if exif:
+        exif_data = Image.Exif()
+        try:
+            exif_data.load(exif)
+        except SyntaxError:
+            pass
+        else:
+            orientation_tag = next(
+                k for k, v in ExifTags.TAGS.items() if v == "Orientation"
+            )
+            exif_orientation = exif_data.get(orientation_tag) or 0
+
     xmp = info.get("xmp", im.info.get("xmp") or im.info.get("XML:com.adobe.xmp"))
 
     if isinstance(xmp, text_type):
@@ -187,6 +204,7 @@ def _save(im, fp, filename, save_all=False):
         autotiling,
         icc_profile or b"",
         exif or b"",
+        exif_orientation,
         xmp or b"",
         advanced,
     )

src/pillow_avif/_avif.c

@@ -139,6 +139,118 @@ exc_type_for_avif_result(avifResult result) {
     }
 }
 
+static void
+exif_orientation_to_irot_imir(avifImage *image, int orientation) {
+    const avifTransformFlags otherFlags =
+        image->transformFlags & ~(AVIF_TRANSFORM_IROT | AVIF_TRANSFORM_IMIR);
+
+    //
+    // Mapping from Exif orientation as defined in JEITA CP-3451C section 4.6.4.A
+    // Orientation to irot and imir boxes as defined in HEIF ISO/IEC 28002-12:2021
+    // sections 6.5.10 and 6.5.12.
+    switch (orientation) {
+        case 1:  // The 0th row is at the visual top of the image, and the 0th column is
+                 // the visual left-hand side.
+            image->transformFlags = otherFlags;
+            image->irot.angle = 0;  // ignored
+#if AVIF_VERSION_MAJOR >= 1
+            image->imir.axis = 0;   // ignored
+#else
+            image->imir.mode = 0;   // ignored
+#endif
+            return;
+        case 2:  // The 0th row is at the visual top of the image, and the 0th column is
+                 // the visual right-hand side.
+            image->transformFlags = otherFlags | AVIF_TRANSFORM_IMIR;
+            image->irot.angle = 0;  // ignored
+#if AVIF_VERSION_MAJOR >= 1
+            image->imir.axis = 1;
+#else
+            image->imir.mode = 1;
+#endif
+            return;
+        case 3:  // The 0th row is at the visual bottom of the image, and the 0th column
+                 // is the visual right-hand side.
+            image->transformFlags = otherFlags | AVIF_TRANSFORM_IROT;
+            image->irot.angle = 2;
+#if AVIF_VERSION_MAJOR >= 1
+            image->imir.axis = 0;  // ignored
+#else
+            image->imir.mode = 0;  // ignored
+#endif
+            return;
+        case 4:  // The 0th row is at the visual bottom of the image, and the 0th column
+                 // is the visual left-hand side.
+            image->transformFlags = otherFlags | AVIF_TRANSFORM_IMIR;
+            image->irot.angle = 0;  // ignored
+#if AVIF_VERSION_MAJOR >= 1
+            image->imir.axis = 0;
+#else
+            image->imir.mode = 0;
+#endif
+            return;
+        case 5:  // The 0th row is the visual left-hand side of the image, and the 0th
+                 // column is the visual top.
+            image->transformFlags =
+                otherFlags | AVIF_TRANSFORM_IROT | AVIF_TRANSFORM_IMIR;
+            image->irot.angle = 1;  // applied before imir according to MIAF spec
+                                    // ISO/IEC 28002-12:2021 - section 7.3.6.7
+#if AVIF_VERSION_MAJOR >= 1
+            image->imir.axis = 0;
+#else
+            image->imir.mode = 0;
+#endif
+            return;
+        case 6:  // The 0th row is the visual right-hand side of the image, and the 0th
+                 // column is the visual top.
+            image->transformFlags = otherFlags | AVIF_TRANSFORM_IROT;
+            image->irot.angle = 3;
+#if AVIF_VERSION_MAJOR >= 1
+            image->imir.axis = 0;  // ignored
+#else
+            image->imir.mode = 0;  // ignored
+#endif
+            return;
+        case 7:  // The 0th row is the visual right-hand side of the image, and the 0th
+                 // column is the visual bottom.
+            image->transformFlags =
+                otherFlags | AVIF_TRANSFORM_IROT | AVIF_TRANSFORM_IMIR;
+            image->irot.angle = 3;  // applied before imir according to MIAF spec
+                                    // ISO/IEC 28002-12:2021 - section 7.3.6.7
+#if AVIF_VERSION_MAJOR >= 1
+            image->imir.axis = 0;
+#else
+            image->imir.mode = 0;
+#endif
+            return;
+        case 8:  // The 0th row is the visual left-hand side of the image, and the 0th
+                 // column is the visual bottom.
+            image->transformFlags = otherFlags | AVIF_TRANSFORM_IROT;
+            image->irot.angle = 1;
+#if AVIF_VERSION_MAJOR >= 1
+            image->imir.axis = 0;  // ignored
+#else
+            image->imir.mode = 0;  // ignored
+#endif
+            return;
+        default:  // reserved
+            break;
+    }
+
+    // The orientation tag is not mandatory (only recommended) according to JEITA
+    // CP-3451C section 4.6.8.A. The default value is 1 if the orientation tag is
+    // missing, meaning:
+    //   The 0th row is at the visual top of the image, and the 0th column is the visual
+    //   left-hand side.
+    image->transformFlags = otherFlags;
+    image->irot.angle = 0;  // ignored
+#if AVIF_VERSION_MAJOR >= 1
+    image->imir.axis = 0;   // ignored
+#else
+    image->imir.mode = 0;   // ignored
+#endif
+}
+
 static int
 _codec_available(const char *name, uint32_t flags) {
     avifCodecChoice codec = avifCodecChoiceFromName(name);
@@ -208,6 +320,7 @@ AvifEncoderNew(PyObject *self_, PyObject *args) {
     int qmax = 10;                           // "High Quality", but not lossless
     int quality = 75;
     int speed = 8;
+    int exif_orientation = 0;
     PyObject *icc_bytes;
     PyObject *exif_bytes;
     PyObject *xmp_bytes;
@@ -223,7 +336,7 @@ AvifEncoderNew(PyObject *self_, PyObject *args) {
 
     if (!PyArg_ParseTuple(
             args,
-            "IIsiiiissiiOOSSSO",
+            "IIsiiiissiiOOSSiSO",
             &width,
             &height,
             &subsampling,
@@ -239,6 +352,7 @@ AvifEncoderNew(PyObject *self_, PyObject *args) {
             &autotiling,
             &icc_bytes,
             &exif_bytes,
+            &exif_orientation,
             &xmp_bytes,
             &advanced)) {
         return NULL;
@@ -404,6 +518,7 @@ AvifEncoderNew(PyObject *self_, PyObject *args) {
                 (uint8_t *)PyBytes_AS_STRING(xmp_bytes),
                 PyBytes_GET_SIZE(xmp_bytes));
         }
+        exif_orientation_to_irot_imir(image, exif_orientation);
 
         self->image = image;
         self->frame_index = -1;

wheelbuild/config.sh

@@ -521,6 +521,8 @@ function install_cmake {
     else
         if [[ "$MB_ML_VER" == "1" ]]; then
             $PYTHON_EXE -m pip install 'cmake<3.23'
+        elif [ "$MB_PYTHON_VERSION" == "2.7" ]; then
+            $PYTHON_EXE -m pip install 'cmake==3.27.7'
         else
             $PYTHON_EXE -m pip install cmake
         fi